September 10, 1998
Hunting for Fort Clatsop: How UW archaeologists are trying to find Lewis and Clark’s winter camp
The exact location of Fort Clatsop, Lewis and Clark’s winter camp near the Oregon Coast, has eluded searching archaeologists for more than half a century. The wooden fort, built and occupied during the winter of 1805-06 after the explorers had crossed North America, has long since rotted away. The site, now Fort Clatsop National Memorial, was homesteaded in the late 19th century and farming activity helped obliterate traces of the fort.
This month, anthropology professor Julie Stein heads a team of archaeologists from the University of Washington and its Burke Museum of Natural History and Culture who are joining the hunt for the fort. The UW team, one of three currently working at the site, is taking a new approach by trying to locate privies and a garbage dump used by Lewis and Clark and the Corps of Discovery. Remote sensing by magnetometer of the entire memorial, done by the National Park Service earlier in the decade, detected about 100 anomalies in the landscape. Stein believes some of the anomalies may be privies. The only way to know if a privy was used by the expedition is to test soil samples for mercury. Lewis and Clark prescribed and gave fairly high doses of mercury to their men as a remedy for syphilis. Privies used by local Indians and later white settlers would not contain mercury.
The UW archaeologists are using an auger, which makes a circular hole about the size of a hole on a golf green, to collect soil samples from the anomalies. Stein and her team are looking for traces of phosphates, which are found in deposits enriched by such things as mammal excrement or bones. It’s also found in bones, which are made of calcium phosphate. The soil samples collected from depths of 20 and 40 centimeters will be tested for phosphate levels by Roger Kiers, a UW anthropology graduate student. Those that are high in phosphates will be sent to Ralph Turner, an expert in mercury analysis at Frontier Geosciences in Seattle.
Stein is also eager to locate the fort’s garbage dump, where vast quantities of elk bones were tossed. Elk was the primary food source for the Corps of Discovery. She thinks the dump may have been at the bottom of an embankment near the site of the present day replica of Fort Clatsop. Stein believes finding either privies or the garbage dump would give researchers a major clue to the exact location of the wooden fort. Lewis and Clark, she says, were by-the-book soldiers, and early 19th century U.S. Army regulations spelled out where privies and garbage areas were to be located in relationship to a fort or camp. In addition, those regulations outlined the dimensions of the fort. Drawings from the journals of Lewis and Clark indicate that they built the original 50-by-50-foot Fort Clatsop to specifications.
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For more information, contact Stein at (206) 685-2282 or jkstein@u.washington.edu
