I submitted the following paper to "Northwestern Naturalist," but their reviewer felt that it contained "nothing new." Obviously, I disagree, or I wouldn't have taken all the time to prepare the manuscript. The likely field of interest is small, so I feel no inclination to put it in another format for another journal. As an alternative, I present it here with the anticipation that it may further the discussion of reintroducing California condors to the Pacific Northwest - Sandy Wilbur.

ABSTRACT-California Condors (Gymnogyps californianus) were found in northern California and Oregon until about 1900. Two hypotheses had been presented concerning their status: they were birds that came north from central California in response to food availability, or they were resident in the area. Evaluation of historic records shows that no food shortages occurred in California that were likely to have modified well-established behavior patterns of condors, forcing them north hundreds of miles from their traditional home range. Archeological and Native American records show that condors were in the Northwest thousands of years, and were too well-known in pre-Caucasian times to have been only intermittent visitors. No nests were found north of San Francisco Bay, but no one looked for them, and they could easily have escaped notice in the rough mountainous terrain. Condor disappearance cannot be fully explained, but at least 24 deaths from shooting are known, enough to start a decline in a population not used to any mortality beyond old-age and accidents. Other undocumented human-caused deaths appear likely. There don't seem to be any habitat deficiencies that would prevent California Condors from living in the Pacific Northwest, should they be reintroduced.

KEY WORDS-California Condor, Gymnogyps, food supply, Native Americans, migration, mortality, California, Oregon

California Condors (Gymnogyps californianus) occurred in the Pacific Northwest until the early 1900s. Carl Koford (1953:9), the first to attempt an evaluation of the species' status beyond central and southern California, thought that all condor records north of San Francisco were of non-breeding birds that periodically or irregularly wandered out of their usual range. Adding to the information available to Koford, I speculated (Wilbur 1973) that California Condors in the Northwest were not merely wanderers, but were resident north at least to the Columbia River area of Oregon and Washington. Koford reviewed my work, but did not think I presented enough new data to change his opinion (pers. comm. June 1974). Now, 35 years later, I think there is sufficient information to support my original conclusion that condors were not visitors to the Northwest, but were permanent residents.
In this review, I present the records of California Condors in the Northwest, putting them in context with the strengths and weaknesses of the available data. I hypothesize as to the past status of condors in the region, and speculate as to the timing and causes of their disappearance.

THE RECORD

For this discussion of California Condor status and distribution, the "Pacific Northwest" is defined as California north of a line drawn from San Francisco to Sacramento, plus Oregon, Washington, Idaho, Montana, and British Columbia and Alberta, Canada. This is the area in which Koford (1953:9) thought all condor records represented wanderers from the south. To better evaluate the data, I have divided the area into 8 districts, loosely based on distance from Koford's presumed resident population, general ecological conditions and human influences, and the strength of the available local information. I use these delineations merely for convenience discussing the records, and do not mean to imply any separation of condor populations between them.

NORTH SAN FRANCISCO BAY (MARIN, NAPA, SONOMA, AND LAKE COUNTIES)
In this area, condors were apparently widespread and common through the mid-1800s, with some persisting until after 1900. Among the Native Americans of the area, all Pomo divisions were well acquainted with condors and had specific words identifying the species (Barrett 1908). The Southern Pomo, Eastern Pomo, Southeastern Pomo, and Coast Miwok are known to have included a condor dance in their annual dance cycle (Loeb 1926; Barrett 1952; Simons 1983). Whole condor skins were used in ceremonies, as were skirts and robes made of condor feathers. Condor bones were made into whistles and ear ornaments, and condor fat was used as a medicine (Barrett 1952). Among the Pomo oral tradition, there is the suggestion that young condors were taken from nests and raised in captivity (although this remembrance was apparently not strong) (Barrett 1952).
In 1840-1841, following Russian settlement of the Sonoma County coast, a number of condor skins and condor feather capes were collected (Vaughan 1971; L. A. Portenko, Zoological Institute, St. Petersburg, Russia, pers. comm.). Condors were seen near Fort Ross, Sonoma County, ca 1845-1846 (Finley 1937). In Napa County, condors were seen "in great abundance" in August 1845, and one was killed there in September 1845 (Clyman 1926). In nearby Marin County in July 1847, more than a dozen condors came to feed on a deer carcass (Bryant 1891). Between 1857 and 1860, condors were frequently seen in the Napa Valley, usually two or three together (Leach 1929). Numbers seem to have declined after 1860, but one was collected in Marin County between 1900 and 1905 (E. R. Blake, Field Museum of Natural History, Chicago, IL, pers. comm.).
The few specific dates available for condor sightings in this district are in summer (July, August, September), when they could have represented either breeding or non-breeding birds. The prominent role given to condors in Native American life in this area suggests much more than a passing familiarity with birds periodically visiting the area.

NORTHWEST CALIFORNIA COAST (MENDOCINO, HUMBOLDT, DEL NORTE, AND WESTERN SISKIYOU COUNTIES)
The Native Americans in this sub-region had a strong relationship with the condor. In Mendocino County, all Pomo and Yuki groups had specific words to describe condors (Barrett 1908), as did the Bear River group in coastal Humboldt County (Goddard 1929). Karuk and Humboldt County Wiyot had myths in which the condor figured prominently (Gifford and Block 1930; Harrington 1932). A condor dance was part of the annual dance cycle of the Pomo in Mendocino County, and also the Coast Yuki (Barrett 1952; Simons 1983). Mendocino County Yuki, and Humboldt County Hupa and Sinkyone viewed the condor as a principal source of shamanistic power (Simons 1983), and condor feathers were used by shamans, in religious ceremonies, and in dance ceremonies by Northern Pomo, Central Pomo, Sinkyone, Kato, Yuki, Coast Yuki, and Wiyot (Kroeber 1925; Barrett 1952; Simons 1983). The Pomo oral tradition that condors may have been taken from nests and raised in captivity (Barrett 1952) gains interest when considering that a Pomo campsite in the Hopland area of Mendocino County had a name translated as "condor hole" (Barrett 1908).
Most of the early Caucasian exploring parties avoided the North Coast, and there was little European settlement of the area until after 1900. Consequently, there are few published records of condors in the area. In May 1828, Jedediah Smith saw "large and small buzzards" (which he differentiated from the eagles, ravens and hawks he also saw) in the Klamath River area near the present-day Humboldt-Del Norte counties line (Sullivan 1934). A few were seen in Mendocino County (location and season unspecified) in the 1870s (Belding 1878), and two were shot in the hills of central Humboldt County (between 1888 and 1892, both in the fall) (Smith 1916). Condors were allegedly plentiful in Humboldt County in "early days" (Smith 1916). In the fall of 1912 one condor was reported in a remote area near the Humboldt County coast. The observer had two specimens of condors in her museum, so knew their characteristics (Cecile Clark, Clarke Museum, Eureka, CA, pers. comm.).
The abundance of Native American records of condors, coupled with specific reports from both spring and fall in the 1800s, suggests the Northwest Coast area supported more than occasional vagrant birds. The area extends 150 to 300 miles from the nearest identified condor nesting areas, which in my opinion is a distance much too great to be covered regularly by condors originating south of San Francisco Bay.

SACRAMENTO VALLEY AND NORTHERN CALIFORNIA MOUNTAINS [SOLANO, YOLO, SACRAMENTO, PLACER, YUBA, BUTTE, PLUMAS, TEHAMA, SISKIYOU AND SHASTA COUNTIES]
Most Native American groups in the lower half of the Sacramento Valley knew condors well, and the species played a strong role in their religion, culture, and ceremony. Patwin, River Patwin, Valley Nisenan, Valley Maidu, and Konkow included a condor dance (called "moloko," or similar name) in their annual dance cycles. They wore the full skins of condors when they danced (Bates 1983; Kroeber 1925; Simons 1983). Condors figured prominently in the myths of the Valley Nisenan (Kroeber 1929), and were perceived as a great source of shamanistic power by Hill Patwin and Konkow (Simons 1983). As was the case along the northern California coast, knowledge of and interest in condors appears to have been much greater than one would have expected for a species that only showed up in the area occasionally.
There are a significant number of written records of condors in the Sacramento Valley and the surrounding mountains. Members of the Wilkes Expedition saw several birds north of Redding in early October 1841, and more in mid October 1841 as the party proceeded down the Sacramento Valley toward Sacramento (Poesch 1961). Condors were seen near Sacramento in 1846 (month not given) (Wilbur 1941:42), and one was shot near the mouth of the Feather River in September 1849 (Johnson 1967). The Bruff party of gold seekers killed one condor in the mountains south of Mt. Lassen in late October 1849, and saw condors there through the winter of 1849-1850 (Reed and Gaines 1949:204-311). In July and August 1854, members of the Pacific Railroad Survey saw condors daily on their march up the Sacramento Valley and through the Siskiyou Mountains to the Klamath Basin, and had "many opportunities of shooting them" (Newberry 1857:73). Condors were occasionally seen in the Sacramento Valley (in winter, and perhaps other seasons) in Yuba and Butte counties in the 1870s (Belding 1878, 1879, 1890), and in the mountains south of Mt. Lassen in 1884 (no month given) (Townsend 1887). There are no certain records after the 1880s, but there is a well-described spring 1925 sighting of six birds identified as condors in a remote area of Siskiyou County (Henry Frazier, Morro Bay, CA, pers. comm.). This observation, plus post-1900 sightings in southwestern Oregon (Finley 1908; Gabrielson and Jewett 1940; Peck 1904), might indicate that a small population of condors remained in this isolated region for many years after they had disappeared from more populated areas.
Many of these condor observations were made 200 to 300 air miles north of the nearest known condor nesting areas. There are records for most months of the year, including in winter when one would expect most condors to be congregated near nesting areas. This further suggests that the condors seen in this area were resident there, nesting in the Coast Ranges, the Sierra foothills, or both.

SOUTHWEST OREGON [CURRY, COOS, JOSEPHINE, JACKSON, AND DOUGLAS COUNTIES]
There is not as strong a record of interrelationships between California condors and southwest Oregon Native Americans as there is in adjacent parts of California. Many of the local groups had been reduced almost to extinction by the early 1800s; this, and the gathering up of various remnants and forcing them on to reservations distant from their home territories, undoubtedly broke traditions and resulted in the loss of some oral history. Nevertheless, David Moen (Oregon Zoo, Portland, OR, pers. comm.) found photographs and preserved specimens of condor feathers used in Karuk dances within a few miles of the Oregon-California border, and learned of at least one Kalapuya myth involving "Grandfather Buzzard." One condor bone, considered pre-Caucasian, was found in a shellmound kitchen midden near Brookings, Curry County, Oregon (Miller 1957).
In October 1826, David Douglas saw "many" condors in the mountains between the Willamette and Umpqua rivers, and reported that Alexander McLeod had seen condors farther south in Oregon about the same time period (Douglas 1914). In late September 1841 Titian Peale saw condors (no numbers given) in the Umpqua watershed, probably near present-day Canyonville, Oregon (Poesch1961). Roselle Putnam, a settler at Yoncalla, Douglas County, saw condors around 1851-1852 (no date or numbers given), and saw one dead condor in that area (Putnam 1928). A condor was rumored to have been killed on the southern Oregon coast ca 1890 (Finley 1908). There are several records of 2-4 condors near Drain, Douglas County, in July 1903 and March 1904 (Finley 1908; Peck 1904). "Several well-informed woodsmen described accurately" condors in southwest Oregon in the early 1900s (Gabrielson and Jewett 1940).
Although the total number of records is not great for this area, I think it is significant that nearly everyone who left a written record of this region before 1855 recorded condors. The region was so lightly settled and so seldom traveled in the late 1800s that even a substantial population of condors might have gone unseen until "discovered" again around 1900. The specific records include March, July, September and October, at least suggesting a resident population in the area.

WILLAMETTE VALLEY [LANE, LINN, MARION AND CLACKAMAS COUNTIES]
Other than the Kalapuya myth involving "Grandfather Buzzard" (David Moen, Oregon Zoo, Portland, OR, pers. comm.), I haven't found any references linking Native Americans and condors in the Willamette Valley. Beginning in the 1770s, the tribes in the Valley were decimated by disease. As occurred in southwest Oregon, the survivors were moved to reservations, sometimes far from their traditional homeland, and some oral history was likely lost.
Before 1850, most Caucasians who wrote reports of this area included records of condors. Some were seen by the party of Alexander Henry and David Thompson, above Willamette Falls (probably Clackamas County) in January 1814 (Coues 1897:817). David Douglas found them "common" in the mid-Valley in October 1826, with nine condors in one flock (Douglas 1914). John Townsend killed one condor near Willamette Falls in April 1834, and later "constantly saw them" (but perhaps the latter statement referred to the Columbia River, not the Willamette) (Townsend 1848). Titian Peale recorded condors "on the plains of the Willamette" in early September 1841 (Peale 1848:58).
Condors in this area, if not resident nearby, were certainly not coming all the way from central California. Because some of the records are from winter and early spring, when one would expect most condors to be congregated near nesting areas, it seems likely that these condors were part of a resident population.

LOWER COLUMBIA RIVER [WA AND OR, FROM THE DALLES, WASCO CO., OR, WEST TO THE PACIFIC OCEAN]
The Native Americans of the Columbia Gorge knew California condors, although the differentiation between the real condor and mythical big birds (e.g. "the Thunderbird") is not as clear-cut there as it was in California. An archeological site near The Dalles, Wasco County, Oregon, yielded condor skeletal parts that showed evidence of feather removal by humans, suggesting that the birds were killed to obtain religious or ritual materials (Hansel-Kuehn 2003).
The Lewis and Clark expedition members saw condors regularly from October 1805 to April 1806, from the vicinity of present-day Cascade Locks, Oregon, downstream to the Pacific Ocean. Specific dates recorded: 28 October 1805, "a few" seen near Cascade Locks; 18 November 1805, one shot near Cape Disappointment, Washington; 29 November 1805, seen (no numbers given) near present-day Astoria, Oregon; early January 1806, apparently regularly seen on the Pacific coast, Clatsop County, Oregon; 16 February 1806, one condor killed in Clatsop County; 4 March 1806, some seen (no numbers given) in present-day Columbia County, Oregon; 15 March 1806, two condors shot, Columbia County, Oregon; 28 March 1806, seen (no numbers given) at Deer Island, Columbia County; and 6 April 1806, one condor shot near Multnomah Falls, Oregon (Lewis and others 2002).
Condors (apparently several) were seen in January 1814 near Cascade Locks (Coues 1897:808). John Scouler collected one (probably near Fort Vancouver, Washington) in the fall 1825 (Scouler 1905). David Douglas apparently saw them regularly near the west end of the Columbia Gorge, with specific observations made in January or February 1826 (including one shot), and in spring 1827, when condors were "ever hovering around" and one was collected (Douglas 1914; Fleming 1924). William Tolmie saw "some" condors feeding on an animal carcass 21 May 1833, on the Cowlitz River not far from its junction with the Columbia (Tolmie 1963:185). Townsend apparently saw them along the lower Columbia River in the spring (and summer?) of 1835 (although his statement may apply only to the Willamette River) (Townsend 1848). The most recent published record was of one near Fort Vancouver in January 1854 (Cooper and Suckley 1860:141).
Condors appear to have occurred along the lower Columbia River throughout the year. Many of the records are in winter and early spring, the time of year when one would expect condors to be congregated near nesting territories. There are many rocky areas that appear suitable for condor nesting.

EAST OF THE CASCADES [EASTERN OR, EASTERN WA, ID, MT, AND ALBERTA, CANADA]
There are only a few records of what appear to have been condors in the Intermountain Northwest. "Vultures of uncommon size" near Walla Walla, Washington, in fall 1818 were likely condors (Ross 1956:137). David Douglas reported seeing condors north to the 49th Parallel (the Canadian border) sometime before 1829; the only places he reached that latitude would have been east of the Cascades. Unfortunately, he gave no specific observations (Douglas 1829). Two condors were reported near Boise, Idaho, in fall 1879, feeding on a sheep carcass (Lyon 1918). No details were given to help judge the validity of the sighting. A September 1897 sighting of a condor near Coulee City, Washington, was made by someone who was familiar with condors in California (Jewett and others 1953). Blackfoot tribal members in Montana and Alberta remember individual large birds appearing occasionally in their area before 1900; some of the descriptions could have been of condors, but some clearly were not (Schaeffer 1951). A published report of two condors near Calgary, Alberta, in September 1896, was almost certainly based on a misidentification of immature Golden Eagles (Aquila chrysaetos) (Fannin 1897; Brooks 1931).
The Walla Walla and Coulee City condors were less than 150 miles from the Columbia Gorge, and within the distance from regularly-used habitat that occasional vagrant condors were seen during the 20th Century. The rarity of condors east of the Cascades is highlighted by the number of people who failed to report them. The Lewis and Clark expedition didn't see any condors in eastern Washington and Oregon in summer and early fall 1805, nor in late spring and summer 1806 (Lewis and others 2002). David Douglas traveled extensively in the Columbia Basin March to August 1826, and passed through the area again in late spring 1827. He was in the Columbia Basin again May to December 1830 (Douglas 1829). If he really did see condors north to the 49th Parallel (Douglas 1829), it would have to have been in this area. It is puzzling that his journals provide no specific condor records in this area, considering how detailed his written observations were during his time west of the Cascades.
Frequently repeated information originating with John Townsend and published by Audubon (1839) was that condors were found 500 miles from the mouth of the Columbia River. This was apparently hearsay, and Townsend failed to see any condors while traveling through the Columbia Basin August-September 1834, or during June-September 1836 (Townsend 1839). Railroad Survey biologists in the southern Washington Cascades and Columbia Basin didn't see condors August-November 1853 (Cooper and Suckley 1860), nor did Railroad Survey personnel traveling up the east side of the Cascades from Klamath Lake to The Dalles August-September 1854 (Newberry 1857:73). J. K. Lord traveled from Klamath Lake to The Dalles May-July 1860; again, no condors were seen (Lord 1866). A number of other well-known ornithologists who observed birds in eastern Oregon between 1874 and 1889 also failed to see condors (Brewer 1875; Henshaw 1880; Cope 1888; Mearns 1879; Merrill 1888; Gonzales 1889).

WESTERN WASHINGTON AND BRITISH COLUMBIA, CANADA
There are no specific records of California condors away from the Columbia River in Washington State. There are scattered records for southwestern British Columbia, where condors reportedly "used to be common" (Rhoads 1893): 1860s, mouth of Fraser River (Lord 1866); September 1880, two seen at Burrard Inlet (Fannin 1891; Kermode 1904); ca 1890, Lulu Island (Rhoads 1893). Farther north in British Columbia, William Tolmie saw what could have been a condor 24 November 1834 at Ft. McLoughlin (Tolmie 1963:293). None of these sightings were well documented, and all have been questioned on various grounds. It seems unlikely that all were misidentifications. Probably condors did periodically wander north, as they apparently wandered east of the Cascade Mountains on occasion.

From the record presented above, it should be clear that the California Condor was not rare north of San Francisco Bay, but was a regularly occurring member of the Pacific Northwest avifauna for 10,000 years or more. Were condors visiting the area from the south, or were they resident in the Northwest? When and why did they disappear?

THE HYPOTHESIS OF NON-RESIDENCY
While Koford conceded that "the occurrence and disappearance of condors along the Columbia River cannot be satisfactorily explained on the basis of available facts" (Koford 1953:9), he remained convinced through his life there had been no resident condors north of San Francisco Bay. His objections to the presence of a resident population were that no fossil or sub-fossil specimens of condors had been found in the area, and no nesting records had been confirmed. His hypothesis for the presence of condors in the Northwest was that the visits were responses to availability of food.
ARCHEOLOGICAL RECORDS.--No Pleistocene remains of condors have so far been discovered in Oregon, but Samwel Cave and Potter Cave in Shasta County, California, have yielded bones (Miller 1911). Pleistocene condors are generally considered to be G. amplus, somewhat larger than the modern California Condor.
Pre-Caucasian condor artifacts have been found, dating from a few hundred to 10,000 years old. The most significant location is the The Dalles Roadcut, Wasco County, Oregon, where remains of at least 22 condors were excavated. These bones were deposited from 11,000 to 8,000 years ago (Miller, 1957; Hansel-Kuehn 2003). A condor bone from a midden near Brookings, Curry County, Oregon, was described as "not very old, though entirely pre-caucasian" (Miller 1942). A condor mandible found with human remains near Sacramento, California, was thought to be 2500 to 3000 years old (Simons 1983). I think these records, combined with the many other Native American reports cited above, rule out the possibility that condors were merely occasional vagrants north of San Francisco Bay. They do not disprove a seasonal movement into the area, but show a long history of condors in the Northwest that is at odds with Koford's belief in a more recent, food-related movement north.
LACK OF NESTING RECORDS.--There are anecdotal records by Native Americans of condors nesting in the Columbia Gorge and in southwestern Oregon (David Moen, Oregon Zoo, Portland, OR, pers. comm.; Schlick 1994). No nest sites have been identified, but no one looked for them while condors occurred in the Northwest. Explorers affiliated with fur trading companies or government expeditions made many of the condor observations. These explorers spent most of their time in the river valleys, the main travel routes through the region. Not surprisingly, then, most condor observations were made in the river valleys, of birds flying or feeding, not associated with potential nests or roosts. The few scientists who made their way deeper into mountainous areas (for example, David Douglas and Titian Peale in the Umpqua River area of southwest Oregon) merely passed through, with no time for pursuing birds away from the expeditions' established travel routes.
The one early exploring party in northwestern California, Jedediah Smith's group in 1828 (Sullivan 1934). saw condors. Smith recorded the sighting, but his party was too busy trying to survive to look for birds' nests. In all the Pacific Northwest west of the Cascades and Sierra Nevada, the scientific surveys had ended by 1855, and for the next 50 years the sparse Caucasian population had little time for the pursuit of natural history. The climate and the cultural environment of central and southern California attracted many people with the time and interest to study wildlife and collect birds' eggs. In contrast, the Northwest was populated mainly by homesteaders, miners, and the city merchants needed to support them. Few of these people left any kind of systematic records, and few mentioned birds. I have found no publications on birds of northwestern California between 1828 and 1887, and only five significant papers on birds of that area between 1887 and 1906 (Grinnell 1909, 1924, 1939). For western Oregon, I found only six papers on birds written between 1855 and 1895, and most of these were brief notes of birds seen near the Willamette Valley population centers (Jobanek 1997). After 1855, the first bird reference I can find for southwestern Oregon was from 1893 (Andrus 1893). In other words, for nearly fifty years almost no one was looking for birds or birds' nests in the Pacific Northwest.
AVAILABILITY OF FOOD FOR CONDORS.-- Koford (1953:9-11) speculated that condors went north of their breeding range either because there was a particularly desirable food source that attracted them, or because they were forced north by food shortages in central and southern California. In his opinion, regular movements into the Northwest could have been a learned behavior within the population: in a time of dire need, condors found a preferred food source that they returned to even after the impetus for long-distance travel was gone.
Some aspects of condor population behavior go against a migration-for-food hypothesis. First, although condors are capable of traveling great distances, there are no 20th Century records of condors (breeding or non-breeding) farther than 150 to 200 miles from a known nesting area (Wilbur 1978a:27, 2004:236). In the 1930s and 1940s, Koford (1953:52) found that most foraging by condors occurred within 35 miles of regularly used roosts, similar to what I observed in the 1970s. In the early 1980s, Meretsky and Snyder (1992) equipped several condors with radio transmitters, and found most activity to be within 50 miles of nesting areas. Food for condors was drastically reduced in the 20th Century compared to the previous hundred years (Wilbur 1978a:27-31), yet no scarcity forced condors to move beyond their expected range.
Second, in the 20th Century, condors were very predictable in their seasonal movements north and south, away from and back toward nesting areas. Expected changes occurred regardless of local food availability. For example, condors moved south from summer roosts in the Sierra Nevada by September, although there was more potential food (dead livestock) in fall and winter than in summer. Similarly, movements north from nesting areas began by April, at which time local food supplies were still near their peak (Wilbur 1978a:7-12). Regular provision of carcasses in one feeding area from 1972 through 1977 failed to disrupt these expected movements. When condors were in the area, they used the supplemental food; when it was "time to go," they left (Wilbur and others 1974; Wilbur 1978b).
Third, while condors occupied the predominantly forested, often cloudy and rainy portions of western Oregon and northwestern California, their body characteristics and behavior are clearly better suited to areas with greater amounts of open space and sunlight. Condors have high wing loading (the ratio of weight to supporting surface; Fisher 1946:572), which results in a relatively short period each day when the atmosphere has warmed enough to develop the ascending currents needed for soaring flight. For California condors, this "soarability" (Hankin 1913:26) is only 5 to 6 hours in winter, and 7 to 8 in summer (Koford 1953:52). Not only is the amount of time for foraging limited, the condors' late rising insures that they will be left with whatever food the earlier, more efficient scavengers leave them. In practice, this has meant that most of their food supply comes from large mammals, native or domestic, who most often inhabit grasslands and other open habitat. They were more likely to have this kind of habitat and type of food in the valleys of California than farther to the north.
Considering the tenacity with which 20th Century condors maintained their close ties to known nesting and roosting areas, and the seasonal regularity of their movements, it is difficult to picture a food situation either so dire or so attractive that condor behavior would be modified in the way Koford hypothesized.
Actually, there is no evidence that any food shortage occurred in central or southern California that might have been severe enough to cause unusual movement of condors. In the 1770s, in the earliest written accounts of California travel, Pronghorn (Antilocapra americana), Elk (Cervus canadensis), and Black-tailed Deer (Odocoileus hemionus) were usually recorded as common to abundant (Burcham 1957:108-110; McCullough 1969:15-24). A one-day hunt in the mountains near Monterey in November 1833 resulted in the killing of 93 black-tailed deer, verified by the hunters displaying all 93 tongues (Leonard 1934). In April 1844, Fremont (1852) found the San Joaquin Valley near the Merced River "crowded with bands of elk and wild horses." The party "frequently started elk, and large bands were seen during the day, with antelope and wild horses." In the northern San Joaquin Valley in September 1846, Bryant (1848) saw "large droves" of antelope, elk, deer, and wild horses, and commented that "game of all kinds appears to be very abundant in this rich valley." Large herds of domestic cattle were in the San Joaquin Valley by 1820 (McCullough 1969:19), and by 1846 Bryant (1848) noted that "beef in
California is so abundant, and of so fine a quality, that game is but little hunted, and not much prized." Cattle were killed in great numbers for their hides and tallow, one "competent authority" estimating that 5 million hides were exported from California between 1800 and 1848 (J. F. Dobie in Burcham 1957:137), leaving most of the meat in the field for scavengers.
The Sacramento Valley, north of the area that Koford considered resident range of the condors, also had large numbers of mammals. The accounts of the Wilkes Expedition in October 1841 reported that "game abounded, elk, antelopes, deer and bears;" observed "numerous bands of animals now covering the plains;" and saw "many small herds of antelopes and elk" (Poesch 1961:195-196). If scarcity of food had been the impetus for condor travel north of San Francisco Bay, they would have had no need to go farther than the Sacramento Valley. During this same period of "abounding" game in California, travelers in western Oregon were seeing Elk, Black-tailed Deer, and White-tailed Deer (Odocoileus virginianus), and sometimes reporting them as "plentiful" or "abundant." Usually, however, they saw only scattered herds, and often could not kill enough to feed their parties (Lewis and others 2002; Douglas 1914; Poesch 1961).
Koford (1953:9) suggested two special food situations, either of which might have been the original attraction that drew condors north from central California. The first was the potential availability of many mammals killed during the extensive fires set each year by Native Americans. The other was the tremendous biomass of spawned salmon that died along the Columbia River and its tributaries. I could find no evidence of large numbers of mammals being killed in the frequent fires. In any event, burning of the land by Native Americans was also extensive and long-term in California (Anderson and Moratto 1996, Keeley 2002), so the practice conferred no particular advantage on Oregon.
In hypothesizing about the importance of the Columbia salmon runs, Koford himself expressed concern that the actual record of condors feeding on salmon was confused because "hearsay is not always separated from fact." A close examination of the written record shows that John Kirk Townsend was the only person who ever claimed to have seen condors feeding on dead salmon. All other reports are apparently hearsay, based either on Townsend's one specific comment on the subject (Townsend 1848), or on a letter from Townsend that was included in Audubon's "Ornithological Biography" (Audubon 1839). Even Townsend's reports on the subject are confusing. In his 1848 paper, he said "during the spring (1835), I constantly saw the Vultures at all points where the Salmon were cast upon the shore." In his letter to Audubon, he repeated the information that condors were most common in spring, but later in the same letter, he wrote: "It (the condor) is seen on the Columbia only in summer, appearing about the first of June, and retiring, probably to the mountains, about the end of August. It is particularly attracted to the vicinity of cascades and falls, being attracted by the dead salmon which strew the shores of such places"
Vultures are opportunistic scavengers, and condors may have eaten dead salmon along the Columbia River more often than is factually documented. Whether they did or not, spent salmon could not have been the special attractant that lured condors north. During the same period that condors were found along the Columbia River, salmon were abundant in the Sacramento-San Joaquin rivers drainage. Use of the salmon by Native Americans throughout interior California is extensively documented. The spring run of Chinook salmon in the San Joaquin River in the early 1800s has been described as "one of the largest Chinook salmon runs anywhere on the Pacific Coast," possibly numbering 200,000 to 500,000 spawners annually. Similar claims have been made about the Sacramento River, which had "the sole distinction among the salmon-producing rivers of western North America of supporting four runs of Chinook salmon - spring, fall, late-fall and winter runs" (Yoshiyama and others 2001). Chinook were the most abundant salmonids, but the Central Valley river system also supported four other species (Williams 2006). Condors were never reported feeding on fish in California, but there was no need to go to Oregon for them, had the condors wanted them.

THE RESIDENT SPECIES HYPOTHESIS
The historical record does not support Koford's speculations that condors were in the Northwest because of food supply, nor would the required long distance flights of condors fit their observed long-term pattern of seasonal and spatial movements. The alternative to California Condors visiting the Pacific Northwest, either regularly or irregularly, is that they were yearlong residents there.
In the absence of specific nesting records, I can only speculate on the pattern of condor residency in the Northwest. Based on my field investigations of condors in the 1970s, and an in-depth study of the historical record, I think that condors were yearlong residents from the Sierra San Pedro Martír in Baja California Norte, Mexico, north in the western mountains of California and Oregon at least to the Columbia River, perhaps farther. There were also condors resident in the foothills east of the San Joaquin and Sacramento valleys in California. Within their total range, subgroups of condors occurred where suitable nesting and foraging habitat existed together. Condors in each of these subgroups had strong bonds to their specific nesting areas, but two or more subgroups seasonally shared foraging areas located within 50 to 100 miles of their respective nesting hubs. Rarely did individual condors travel more than 100 miles from their home base. Tenacity to a home nesting habitat gave cohesiveness to the subgroup, and for much of the year isolated its members from other condors. The seasonal mixing of subgroups improved the chances of new pair formation, and likely helped maintain diversity in the gene pool of each group (Wilbur 1973, 1978a:7-13, 2004:229-240).

Subgroups such as I hypothesize for condors have been identified in many species of birds. For example, Common Terns (Sterna hirundo) live in small colonies, each of which maintains its membership, even though located only a few miles from other colonies (Austin 1951). Pink-footed Geese (Anser brachyrhynchus)"form closed groups occupying small, well-defined areas" in which "the scale of mixing is negligible" (Boyd 1972). Ducks, crows, ravens, eagles, and Peregrine Falcons are other species that have been shown to have strong "homing" instincts to a particular area and particular group of companions (Hickey 1942; Sowls 1955; Brown 1972).

WHEN DID CONDORS DISAPPEAR FROM THE NORTHWEST?
The observations of California Condors in Douglas County, Oregon in 1903-1904 are usually considered to represent vagrant birds from far to the south, or a few individuals that held on in the area long after most had disappeared (Finley 1908; Koford 1953:9-11; Gabrielson and Jewett 1940). I suspect that isn't true. Reports of condors decreased after 1850, but the lack of records might merely be the result of fewer people looking for them. In the western mountains, the major fur expeditions and scientific surveys had ended, and no other ornithologists had arrived to carry on their natural history reporting. Not only were few naturalists in the area, there were very few other people. The 1860 federal census of northwestern California (Del Norte, Humboldt, Mendocino, Trinity and Siskiyou counties) recorded less than 25,000 people, most of whom were either miners or people living in the lowlands around Humboldt Bay. By 1900, that population increased to 60,000, but most lived at Crescent City, around Humboldt Bay, and around Ukiah, leaving some 20,000 square miles of mountainous habitat essentially uninhabited. The Umpqua River-Rogue River area of southwest Oregon, second only to the lower Columbia River area in total condor records, in 1860 had less than 4000 residents. In 1900, there were still less than 25,000 people in an area of over 8000 square miles of rugged habitat in which condors were unlikely to be conspicuous. The total population of Oregon between 1860 and 1900 increased from 52,000 to 415,000, but over half the people lived in the Willamette Valley between Eugene and Portland. Condors could have been easily overlooked in most of the western mountains of the state.
Considering the ruggedness and isolation of southwestern Oregon and northwestern California, and the sparse human population as late as the early 1900s, it seems possible there was a viable population of condors in the area until sometime early in the 20th Century. Although most observers agreed that condor numbers decreased in the Sacramento Valley and the North Bay regions after about 1860, condors were still being regularly seen at a variety of locations in northern California into the 1880s and early 1890s, with some later records. Clearly, there were still one or more strongholds of condors somewhere north of San Francisco Bay for many years after 1850.

WHY DID CONDORS DISAPPEAR FROM THE NORTHWEST?
Precisely why condors were gone from the Pacific Northwest by the early 20th Century will never be known, but I suspect it occurred because of a combination of three factors:
(1) The Northwest condors were probably living at the margin of habitable range. The habitat was not unsuitable in any way. Condors survived there for hundreds of years, and (as noted by David Douglas and members of the Lewis and Clark expedition) were not noticeably affected by the cloudy, rainy weather of Northwest winters. Nevertheless, it seems logical that a large scavenger like the condor would be better suited to the vast open grasslands of central California, populated with hundreds of thousands of large wild and domesticated mammals, with many more clear days available for foraging. Comparing equal acreages of the Northwest and central California, the latter would almost certainly have a higher scavenger carrying capacity, and likely could support more condors per unit of land than the Northwest habitat. Under pristine conditions, the difference in carrying capacity would not be a problem - the population size would adjust to the amount and quality of available habitat - but might be important as other factors came into play.
(2) The Northwest condor population sustained at least periodic losses from Native Americans, but mortality increased markedly with the arrival of Caucasians in the Northwest. In the rather sparse written record of the area, I found information on 25 condors killed between 1805 and 1900. This may seem like minor loss over almost 100 years, but the balance between reproductive potential and mortality within the condor population was delicate. It took only a very small change in that balance to produce a very large effect. Condors had to live at least 6 years before they reproduced, had one egg per clutch, and typically nested only once every two years. Condors often lived over 20 years, and natural mortality was predominantly caused by old age and accidents, so a low reproductive rate was not a particular liability. The introduction of losses caused by humans quickly upset the balance. Elsewhere, I have hypothesized that the California Condor population never recovered from early human-caused losses, and the major decline in numbers in the 1970s was the result of mortality between 1880 and 1920 (Wilbur 1978a:22, 2004:379-380).
All but perhaps one of the 25 known losses were from shooting, some in the name of science but mostly out of curiosity or specific intent. In the rough frontier setting of the 19th Century Pacific Northwest, it takes little effort to imagine additional mortality. Almost every early journal mentioning condors also recorded the frustrations of killing deer or elk to replenish often critically low larders, only to find that condors and other scavengers had consumed the carcasses before they could be brought into camp. Homesteaders would be wary of very large, unknown birds in proximity to their precious livestock. Young adventurers with rifles and time on their hands have regularly shot at big targets in the sky.
No source of condor mortality other than shooting has been confirmed, but there were certainly other possibilities. The important point to remember is that there didn't have to be one big reason for the condors' disappearance. One mortality factor, probably shooting, may have been particularly important in upsetting the population balance. After that, the combination of a number of lesser factors kept the population from stabilizing.
(3) As suggested above, condors throughout their range appear to have existed in a number of semi-discrete subpopulations, that mixed with adjacent subpopulations at certain seasons but mostly had their own habitat. If a particular subpopulation vanished, or fell below some minimum level, it was unlikely that other condors would move into the vacated area. I think the known losses along the Columbia River could have been great enough to destabilize a subpopulation in that area, and lead to its eventual disappearance. Perhaps the losses of condors in Marin and Sonoma counties, or in the mountains surrounding the Sacramento Valley, prevented the infusion of new condors into northwestern California and southwestern Oregon, and those subpopulations were not large enough to sustain themselves over time.
Here are two examples of how the division of condors into subpopulations led to local extirpations.
(a) Condors had become very rare in Monterey County, California, and vicinity by 1890 or 1900 (Koford 1953:18). For that area between 1870 and 1900, I compiled records of 30 condors killed and 9 eggs collected (Wilbur 1978a:71-88). The mortality records are mostly of birds that ended up in museums; there were surely other condors that were wantonly shot or otherwise died, for which no records survive. This level of loss to a species that had no significant natural enemies, and which died mainly of old age or accidents, had to have a major impact. If, as I believe, little interchange occurred between condor groups to the north and south, the losses would have been disastrous. In fact, although condors continued to be seen occasionally in these counties in later years, there were only a few nesting records after 1910. The area was within 100 miles or so of condors nesting to the south, but there was apparently little or no pioneering of new pairs into this region.
(b) A similar situation occurred in the region from the San Gabriel Mountains south to the Mexican border. According to Koford (1953:18), condors became very rare in this area between 1900 and 1910. Losses I was able to confirm between 1870 and 1910 totaled 38 condors and 7 eggs (Wilbur 1978a:71-88). Again, this accounts for very little indiscriminate killing, so the numbers are surely minimal. Although condors were still relatively common just to the north of the Los Angeles Basin for 60 more years, there are only a handful of condor records for this vast southern coastal area after 1910. Both nesting and feeding habitats were still available, but no birds emigrated to fill the vacant niche.
California Condors have been gone from the Pacific Northwest for 100 years, and it is unlikely any new evidence will be found to clarify their former status. From the information presented above, I think it is clear that condors were resident in the Northwest, not migrants from central California. They had become rare by 1900, probably the result of human-caused mortality, primarily shooting. There is nothing to indicate disappearance was related to habitat changes or deficiencies, and the region should be able to support condors, if they were reintroduced.

LITERATURE CITED

ANDERSON MK, MORATTO MJ. 1996. Native American land-use practices and ecological impacts. Pp. 187-206 in Sierra Nevada Ecosystems Project: Final report to Congress. Volume II, Assessments and scientific basis for management options. Davis (CA): University of California, Centers for Water and Wildland Resources.
ANDRUS FH. 1893. A nest (plum) full. Oologist 10:300.
AUDUBON JJ. 1839. Ornithological biography. Volume 5. Edinburgh, Scotland: Adam & Charles Black. 664 p.
AUSTIN OL. 1951. Group adherence in the Common Tern. Bird-banding 22:1-15.
BARRETT SA. 1908. The ethno-geography of the Pomo and neighboring tribes. Univ. Calif. Publ. Amer. Archeol. Ethnol. 6:1-332.
BARRETT SA. 1952. Material aspects of Pomo culture. Bull. Public Mus. Milwaukee 20:1-508.
BATES CD. 1983. The California collection of I. G. Voznesenski. Am. Indian Art 8(3):36-41, 79.
BELDING L. 1878. Letter Lyman Belding to Robert Ridgway 21 March 1878. Wash. D. C. Smithsonian Institution archives.
BELDING L. 1879. A partial list of the birds of central California. Proc. U. S. Natl. Mus.1:388-449.
BELDING L. 1890. Land birds of the Pacific district. Occasional Papers, Calif. Acad. Sci.2:1-274.
BOYD H. 1972. British studies of goose populations: hindsight as an aid to foresight. Pages 251-262 in Population ecology of migratory birds: a symposium. U. S. Bureau of Sport Fisheries and Wildlife, Wildlife Research Report 2.
BREWER TM. 1875. Notes on seventy-nine species of birds observed in the neighborhood of Camp Harney, Oregon, compiled from the correspondence of Capt. Charles Bendire,1st Cavalry U.S.A. Proc. Boston Soc. Nat. Hist. 18:153-168.
BROOKS A. 1931. Letter from Alan Brooks to W. L. Chambers 6 March 1931. Chambers collection, Museum of Vertebrate Zoology, Berkeley, CA.
BROWN LH. 1972. Natural longevity of wild Crowned Eagles, Stephanoaetus coronatus. Ibis 114:263-265.
BRYANT E. 1848. What I saw in California. New York: D. Appleton and Co. 484 p.
BRYANT WE. 1891. Andrew Jackson Grayson. Zoe 2:34-68.
BURCHAM LT.1957. California range land. Sacramento (CA): California Department of Natural Resources. 256 p.
CLYMAN J. 1926. James Clyman, his diaries and reminiscences. Calif. Hist. Soc. Quart. 6:136-187.
COOPER JG, SUCKLEY G. 1860. Report upon the birds collected on the Survey: Land birds. Pages 140-291 In Explorations for a route for the Pacific Railroad near the Forty-seventh and Forty-ninth Parallels, explored by I. I. Stevens. Wash. D. C.
COPE ED. 1888. Sketches of the Cascade Mountains of Oregon. Am. Nat. 22:996-1003.
COUES E. editor. 1897. The manuscript journals of Alexander Henry and David Thompson, 1799-1814. New York (NY): Francis P. Harper. 1027 p.
DOUGLAS D. 1829. Observations on the Vultur californianus of Shaw. Zool. J. 4:328-330.
DOUGLAS D. 1914. Journal kept by David Douglas during his travels in North America 1823-1827. London: William Wesley & Son. 364 p.
FANNIN J. 1891. Check-list of British Columbia birds. Victoria (British Columbia): Richard Wolfenden. 47 p.
FANNIN J. 1897. The California Vulture in Alberta. Auk 14:89.
FINLEY EL, editor. 1937. History of Sonoma County, California: its people and its resources. Santa Rosa (CA): Press Democrat Publishing Company.384 p.
FINLEY WL. 1908. Life history of the California Condor. Part II, historical data and range of the condor. Condor 10:5-10.
FISHER HI. 1946. Adaptations and comparative anatomy of the locomotor apparatus of New World vultures. Am. Midl. Nat. 35:545-727.
FLEMING JH. 1924. The California Condor in Washington: another version of an old record. Condor 26:111-112.
FREMONT JC. 1852. The exploring expedition to the Rocky Mountains, Oregon and California. Buffalo (NY): Geo. H. Derby. 693 p.
GABRIELSON IN, JEWETT SG. 1940. Birds of the Pacific Northwest. Corvallis (OR): Oregon State University. 650 p.
GIFFORD EW, BLOCK GH. 1930. California Indian nights entertainments. Glendale (CA): Arthur H. Clark Co. 323 p.
GODDARD PE. 1929. The Bear River dialect of Athapascan. Univ. Calif. Publ. Am. Archeol. Ethnol. 24:291-324.
GONZALES B. 1889. Overland journey-Texas to the Pacific. Ornithol. and Oologist 14:161-162.
GRINNELL J. 1909. Bibliography of California ornithology. Pacific Coast Avifauna Number 5. Berkeley (CA): Cooper Ornithological Club. 166 p.
GRINNELL J. 1924. Bibliography of California ornithology, second installment to end of 1923. Pacific Coast Avifauna Number 16. Berkeley (CA): Cooper Ornithological Club. 182 p.
GRINNELL J. 1939. Bibliography of California ornithology, third installment to end of 1938. Pacific Coast Avifauna Number 26. Berkeley (CA): Cooper Ornithological Club. 235 p.
HANKIN EH. 1913. Animal flight. London (England): Iliffe and Sons. 406 p.
HANSEL-KUEHN VJ. 2003. The Dalles Roadcut (Fivemile Rapids) avifauna: evidence for a cultural origin. Master of Arts thesis, Washington State University (Pullman, WA).
HARRINGTON JP. 1932. Karuk Indian myths. Bur. Am. Ethnol. Bull. 107:1-34.
HENSHAW HW. 1880. Ornithological report from observations and collections made in
portions of California, Nevada and Oregon, by assistant H. W. Henshaw. Appendix L of the Report of the Chief Engineers; pages 282-335 in Annual report of the U. S. geographical survey west of the 100th meridian for 1879. Washington D. C: Government Printing Office.
HICKEY JJ. 1942. Eastern populations of the Duck Hawk. Auk 59:176-204.
JEWETT SC, TAYLOR WP, SHAW WT, ALDRICH JW. 1953. Birds of Washington State. Seattle (WA): University of Washington Press. 767 p.
JOBANEK GA. 1997. An annotated bibliography of Oregon bird literature published before 1935. Corvallis (OR): Oregon State University Press. 481 p.
JOHNSON K. 1967. The Gold Rush letters of J. D. B. Stillman. Palo Alto (CA): Lewis Osborne. 75 p.
KEELEY JE. 2002. Native American impacts on fire regimes of the California coastal ranges. J. Biogeog. 29:303-320.
KERMODE F. 1904. Catalogue of British Columbia birds. Victoria (British Columbia): British Columbia Provincial Museum. 69 p.
KOFORD CB. 1953. The California Condor. Research Report No. 4. New York (NY): National Audubon Society. 154 p.
KROEBER AL. 1925. Handbook of the Indians of California. Smithsonian Institution, Bur. Am. Ethnol. Bull. 78. 995 p.
KROEBER AL. 1929. The Valley Nisenan. Univ. Calif. Publ. Am. Archeol. Ethnol. 24:253-290.
LEACH FA. 1929. A Turkey Buzzard roost. Condor 31:21-23.
LEONARD Z. 1934. Narrative of the adventures of Zenas Leonard written by himself. Chicago (IL): Lakeside Press. 317 p.
LEWIS M, CLARK W AND MEMBERS OF THE CORPS OF DISCOVERY. 2002. The journals of the Lewis and Clark Expedition. Lincoln (NE): University of Nebraska Press [cited 2008 17 June]; electronic version: http://lewisandclarkjournals.unl.edu/journals.php?id=1806-09-04
LOEB EM. 1926. Pomo folkways. Univ. Calif. Publ. Am. Archeol. Ethnol. 19(2):149-404.
LORD JK. 1866. The Naturalist in Vancouver Island and British Columbia. London (England): Richard Bentley. 375 p.
LYON JR. MW. 1918. Report of the Secretary, Biological Society of Washington, 20 October 1917. J. Wash. Acad. Sci. 8:25-28.
MCCULLOUGH DR. 1969. The Tule Elk: its history, behavior and ecology. Univ. Calif. Publ. Zool. 88:1-209.
MEARNS EA. 1879. A partial list of the birds of Fort Klamath, Oregon, collected by Lieutenant Willis Wittich, U. S. A., with annotations and additions by the collector. Bull. Nuttall Ornithol.l Club 4:161-166, 194-199.
MERETSKY VJ, SNYDER NFR. 1992. Range use and movements of California Condors. Condor 94:313-335.
MERRILL JC. 1888. Notes on the birds of Fort Klamath, Oregon, with remarks on certain species by William Brewster. Auk 5:139-146, 251-262, 357-366.
MILLER AH. 1942. A California Condor bone from the coast of southern Oregon. Murrelet 23:77.
MILLER L. 1911. Avifauna of the Pleistocene cave deposits of California. Univ. Calif. Bull. Dept. Geol. 6(16):385-400.
MILLER L. 1957. Bird remains from an Oregon Indian midden. Condor 59:59-63.
NEWBERRY JS. 1857. Report upon the birds of the route. Pages 73-110 in Williamson RS, Abbot HL, Report upon Explorations for a Railroad Route, from the Sacramento Valley to the Columbia River. Volume VI, Report of Explorations and Surveys to Ascertain the most Practicable and Economical Route for a Railroad from the Mississippi River to the Pacific Ocean 1854-5. Wash., D. C.
PEALE TR. 1848. Mammalia and Ornithology. Volume VIII, United States Exploring Expedition during the years 1838, 1839, 1840, 1841, 1842 under the command of Charles Wilkes, U. S. N. Philadelphia (PA): C. Sherman. 338 p.
PECK GD. 1904. The Cal. Vulture in Douglas Co., Oregon. Oologist 21(4):55.
POESCH J. 1961. Titian Ramsay Peale 1799-1885 and his journals of the Wilkes Expedition. Philadelphia (PA): American Philosophical Society. 214 p.
PUTNAM R. 1928. The letters of Roselle Putnam. (Transcript and notes by Sheba Hargreaves). Oregon Hist. Quart. 29:242-269.
REED GW, GAINES R, EDITORS. 1949. The journals, drawings and other papers of J. Goldsborough Bruff, April 2, 1849-July 20, 1851. New York: Columbia University Press.
RHOADS SN. 1893. The birds observed in British Columbia and Washington during the spring and summer 1892. Proc. Acad. Nat. Sci. Phila. 45:21-65.
ROSS A. 1956. The fur hunters of the Far West. Norman (OK): University of Oklahoma Press. 304 p.
SCHAEFFER CE. 1951. Was the California Condor known to the Blackfoot Indians? J. Wash. Acad. Sci. 41(6):181-191.
SCHLICK MD. 1994. Columbia River basketry: gifts of the ancestors, gifts of the earth. Seattle (WA): University of Washington Press. Not paged.
SCOULER J. 1905. Dr. John Scouler's journal of a voyage to northwest America. Oregon Hist. Quart. 6:276-287.
SIMONS DD. 1983. Interactions between California Condors and humans in prehistoric far western North America. Pages 470-494 in WILBUR SR, JACKSON JA editors, Vulture Biology and Management. Berkeley (CA): University of California Press. 550p.
SMITH FJ. 1916. Occurrence of the condor in Humboldt County. Condor 18:205.
SOWLS LK. 1955. Prairie ducks: a study of their behavior, ecology and management. Harrisburg (PA): Stackpole Company. 193 p.
SULLIVAN MS. 1934. The travels of Jedediah Smith, a documentary outline including the journal of the great American pathfinder. Lincoln (NE): University of Nebraska Press.
TOLMIE WF. 1963. William Frasar Tolmie, physician and fur trader. Vancouver (British Columbia): Mitchell Press Ltd. 413 p.
TOWNSEND CH. 1887. Field-notes on the mammals, birds and reptiles of northern California. Proc. U. S. Nat. Mus. 10:159-241.
TOWNSEND JK. 1839. Narrative of a journey across the Rocky Mountains to the Columbia River, and a visit to the Sandwich Islands, Chili, &c. Philadelphia (PA): H. Perkins. 290 p.
TOWNSEND JK. 1848. Popular monograph of the accipitrine birds of N. A. -- No. II. Lit. Rec. J. Linnaean Assoc. Pennsylvania College 4(12): 265-272.
VAUGHAN T. 1971. Russian museums: a unique trip by rail. Mus. Quart. 7(3):1-7.
WILBUR ME, editor. 1941. A pioneer at Sutter's Fort, 1846-1850. The adventures of Heinrich Lienhard. Los Angeles (CA): The Calafia Society. 291 p.
WILBUR SR. 1973. The California Condor in the Pacific Northwest. Auk 90(1):196-198.
WILBUR SR. 1978a. The California Condor, 1966-76: a look at its past and future. North American Fauna 72. Wash., D. C: U. S. Fish and Wildlife Service. 136 p.
WILBUR SR. 1978b. Supplemental feeding of California Condors. Pages 135-140 in TEMPLE SA editor, Endangered birds: management techniques for preserving threatened species. Madison (WI): University of Wisconsin Press. 466 p.
WILBUR SR. 2004. Condor tales: what I learned in twelve years with the big birds. Gresham (OR): Symbios. 400 p.
WILBUR SR, CARRIER WD, BORNEMAN JC. 1974. Supplemental feeding program for California Condors. J. Wildl. Manage. 38:343-346.
WILLIAMS JG. 2006. Central Valley salmon: a perspective on Chinook and Steelhead in the Central Valley of California. San Francisco Estuary Watershed Sci. 44(3):1-398.
YOSHIYAMA RM, GERSTUNG ER, FISHER FW, MOYLE PB. 2001. Historical and present distribution of Chinook Salmon in the Central Valley drainage of California. Pages 71-176 in BROWN RL editor, Contributions to the biology of Central Valley salmonids. Fish Bull. 179, Scripps Institution of Oceanography (La Jolla, CA).