Wildlife & Habitat
Umatilla National Wildlife Refuge is intensively managed to provide habitat for migratory birds and resident wildlife. Management practices include the restoration of wetlands, manipulation of seasonal wetlands to encourage native food supplies, farming, prescribed burning, planting native willows and cottonwoods in riparian areas, improving uplands by removing invasive weeds, and planting native grasses.
The building of dams on the Columbia River began in the 1930s and changed it from a narrow, fast-flowing river to a wide, slow-moving reservoir. In some places, the river's depth was raised 25 feet. Many islands, riparian areas, and other habitats were flooded, but other arid lands were transformed into wetlands. Native cottonwoods, willows, cattails and bulrush began to appear in previously deserted desert environments. McCormack Slough in Oregon and Paterson Slough in Washington are good examples of wetlands created by rising Columbia River water levels.
At higher elevations, above the Columbia's reach, the refuge's plant communities are dominated by species capable of tolerating the hot, dry conditions of the Columbia Plateau. Common shrubs include sagebrush, bitterbrush and rabbitbrush. Native bunchgrasses, such as basin wildrye, Indian ricegrass, Idaho fescue, and Sandberg bluegrass, were once common here, but today they must compete with very successful exotic plants such as cheatgrass, knapweed, tumbleweed and perennial pepperweed. Refuge staff are working to remove exotics and replant refuge habitats with native species more beneficial to wildlife.
Islands in the Columbia River are an important sanctuary for birds year round and are closed to public entry. Ducks, Canada geese, great blue herons, and black-crowned night herons nest here in spring and summer. Thousands of ducks and geese winter on the islands, and many different species rest here during spring and fall migration.