Research at Lewis and Clark
The historic Fort Clatsop site was established as a national memorial in 1958 to commemorate the culmination and 1805-06 winter encampment of the Lewis and Clark Expedition on the Oregon coast. In 2004 Congress authorized the expansion of the park from 125 to more than 3,200 acres, including several new units with important historic links to the famous expedition. Development of the newly expanded park and two new hiking trails have constituted valuable legacy projects of the 2004-2006 Lewis and Clark Bicentennial.
Long known as Fort Clatsop National Memorial, the newly renamed Lewis and Clark National Historical Park now rings the ecologically significant Columbia River estuary, with 12 units in southwest Washington and northwest Oregon. Its regional maritime climate is warm and dry in summer and fall, mild and wet in winter and spring. Mean annual precipitation averages 74 inches in the coastal lowlands, mostly as rainfall. The coastal geology consists of Quaternary marine and non-marine terrace deposits and alluvium in the lowlands, with Miocene basalts and marine sandstone, siltstone, and shale in the uplands. Elevations in the park range from sea level on the ocean shores to 300 feet atop Clatsop Ridge.
The park preserves a variety of ecosystems from coastal dunes, estuarine mudflats and tidal marshes to shrub wetlands, temperate rainforests and swamps. Situated within the Sitka spruce vegetation zone, its forests are dominated by conifer trees and carpeted with a great diversity of understory shrubs, ferns and wildflowers. Giant Sitka spruce more than 100 years old and up to 36 feet in circumference are found here. Extensive wetlands in the park include fringing saltmarshes on the lower Columbia River, the tidally-influenced lower Lewis and Clark River and many low-gradient brackish sloughs and marshes. Freshwater streams and springs are numerous in park forests, and freshwater ponds are found in various habitats. These wetlands provide valuable habitat for a diversity of mammals, birds, reptiles, amphibians and fish.
The great variety of flora and fauna in the park reflects its diversity of habitats, location on the Pacific migratory flyway and proximity to the Pacific Ocean. More than 140 species of vertebrates, including at least 44 mammals, 75 birds, 11 amphibians, 3 reptiles and 9 fish pass through or make their permanent home within the park. Over 250 species of vascular plants and 74 of bryophytes have been documented in recent surveys, and most are represented in the park herbarium. Many additional species of invertebrates, fungi and lichens have yet to be inventoried.
The park's natural resources are significant from a historic as well as a contemporary perspective. During the winter of 1805-06, explorers Meriwether Lewis and William Clark described, sketched or collected more than three dozen of the region's plants, including evergreen huckleberry (Vaccinium ovatum) and salal (Gaultheria shallon), both new to science. Their journal entries also documented 23 mammals, 28 birds and several fish, reptiles, amphibians and invertebrates during the expedition's winter stay.