Fossil Lake: Oregon's answer to the LaBrea Tar Pits
Discovered (sort of) by Oregon's first governor, the dry lakebed in south-central Oregon's Lake County is a gold mine of Ice Age fossils, from tiny rodents to wooly mammoths, saber-tooth cats and dire wolves.
The interpretive sign posted at the Fossil Lake area. (Photo by Leroy
By Finn J.D. John — October 17, 2010
As a source of fossil remnants of ancient animals, the LaBrea Tar Pits in California are No. 1 in North America.
But surprisingly close behind is a place in eastern Oregon that few people have ever heard of: Fossil Lake, a dry lakebed in south-central Oregon.
Fossil Lake was actually discovered (sort of) by Oregon’s first state governor, John Whiteaker, in 1875, years after he left office. Of course, cattle ranchers and cowboys already knew about it, but it was the ex-guv, an amateur geologist of sorts, who brought it to the attention of science.
The following year, Whiteaker made a more serious expedition to the place, and the year after that the University of Oregon’s legendary Professor Thomas Condon came. In the ensuing years many more geologists and paleontologists would follow.
How the lake trapped so many animals
Fossil Lake today is really nothing more than a low spot in the high desert. But once, a few hundred thousand years ago, it was part of a single huge lake, more than 100 feet deep, that included the areas we know today as Silver Lake and Christmas Lake.
Over the years, it got deeper and shallower with the seasons; like most Lake County lakes, it had no outlet, so minerals and salts concentrated in its waters.
This is apparently how so many animals came to be preserved in it. Crossing a mud flat to get to the water, they got stuck, sank and died; the salts in the water essentially pickled the animals, retarding the natural processes of decomposition; and over time, the bones petrified — although many of the specimens found there were still new enough that they hadn’t turned to stone yet.
The vast majority of animals there, possibly all of them, are from the Pleistocene era, which started 1.65 million years ago and ended with the last ice age, about 10,000 years ago. That’s the era of such “megafauna” as wooly mammoths, dire wolves and saber-tooth “tigers.” So far as is known, there are no remains from dinosaurs or other pre-Pleistocene animals there.
Most of the animal remains at the Silver Lake site are small mammals, birds and fish; the big creatures, such as the dire wolves, mammoths and Pleistocene-era horses and camels, are getting more and more scarce as the site gets picked over. But there’s a huge variety of animals entombed there, and several species of extinct creatures are known to science only because their bones were found at Silver Lake.
Paleontologists still doing fieldwork
Since 1990, Professor James Martin of the South Dakota School of Mines and Technology has regularly led an upper-division class of students in a two-week field paleontology course at the lake in the late spring. The students stay at the Bureau of Land Management’s fire guard camp at night, pool their resources for communal meals and spend long days on trench excavations and explorations. Their efforts typically yield thousands of fossils, which are added to the public collection at the college.
“Every year we come out here we see something new, something different, something we didn’t understand clarified,” Martin told Lake County journalist Melany Tupper in 2001. “So any study that’s worth its salt is a multi-year study.”
Many fossils are now at University of Oregon
Quite a few specimens from Fossil Lake are in the University of Oregon’s collection, thanks to Professor Condon and his late-1800s expeditions. But fossils from the lake have found their way into several collections nationwide. The American Museum of Natural History houses the bones collected by Edward Drinker Cope, who arrived the same year Condon did; fossils are also housed at the University of California and, of course, the South Dakota School of Mines and Technology.
Fossil Lake is not the only site in Oregon that’s rich in remains of ancient animal life. But in Ice Age paleontology circles, it’s the most well known, and — as the enormous list of different animal types found there attests — easily the most productive.
(Sources: Tupper, Melany. High Desert Roses: Significant Stories from Central Oregon. Bloomington, Ind.: 1stBooks, 2003; Elftman, Herbert O. “Pleistocene mammals of Fossil Lake, Oregon,” American Museum Novitates No. 481. New York: AMNH, 1931; The New York Times, June 4, 1877 (page 8); South Dakota Museum of Geology, http://museum.sdsmt.edu; McCormack, Ellen Condon. “Contributions to the Pleistocene History of Oregon,” Geology Bulletin (Univ. of Ore.), Oct. 1920)