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Fort Vancouver National Historic Site has two units: the Fort Vancouver Unit on the north bank of the Columbia River in Clark County, Washington, and the McLoughlin House Unit along the Willamette River in Clackamas County, Oregon. Together they cover about 84 hectares (207 acres).
The Geologic Resources Inventory report for Fort Vancouver. Image from the National Park Service's Geodiversity Atlas page on Fort Vancouver.
History
| Authorized | June 19, 1948, as a national monument; redesignated a national historic site June 30, 1961 |
| Fort Vancouver | Western headquarters of the Hudson's Bay Company's fur-trade empire and its supply depot west of the Rocky Mountains |
| McLoughlin House | Home of Dr. John McLoughlin, called "the Father of Oregon" for helping American settlers who came west |
| Stories told | Emigration over the Oregon Trail, military history at Vancouver Barracks and aviation history at Pearson Air Museum |
| Collections | Historic buildings and a large collection of American Indian, fur-trade and U.S. Army material — archeological artifacts, objects and archives — reflecting two centuries of global trade, technology and cultural exchange |
Geologic setting
The site lies in the Portland Basin, a rhomboid-shaped depression that began forming in the Miocene, about 20 million years ago, as the Juan de Fuca Plate slid beneath the North American Plate. Four main episodes shaped the region:
- formation of the Portland Basin;
- eruption of enormous volumes of Columbia River Basalt lava, from upwelling mantle;
- the evolution of the Columbia River;
- catastrophic ice age floods that sculpted today's landscape.
The thick fill of the basin records flood basalts, sediment and volcanic debris from near and far, earthquakes, subsidence, river and lake deposits, and flood deposits.
| Unit | What lies beneath |
|---|---|
| McLoughlin House | Only Miocene Wanapum Basalt of the Columbia River Basalt Group |
| Fort Vancouver | Younger Pleistocene Missoula flood deposits and Holocene alluvium of the Columbia River floodplain |
The site belongs to the Puget Trough section of the Pacific Border physiographic province.
Geologic map of Fort Vancouver, from the Geologic Resources Inventory. Image from the National Park Service's Geodiversity Atlas page on Fort Vancouver.
The Park Service's Geologic Resources Inventory maps and reports, and a completed Soil Resources Inventory project, are available through the NPS DataStore.
Archaeologists working on a shallow excavation at Fort Vancouver. Image from the National Park Service's Geodiversity Atlas page on Fort Vancouver.
Sources
Based on "NPS Geodiversity Atlas—Fort Vancouver National Historic Site, Washington and Oregon," National Park Service; a work of the United States government in the public domain.
Nestas publicaçõesFort Vancouver National Historic Site
Licença: CC0 1.0 (domínio público) · Adaptado de www.nps.gov
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