Text modified from Abell et al. 2000. Freshwater Ecoregions of North America: A Conservation Assessment. Island Press, Washington, DC, USA. Additional text provided by J. Hales.
Major Habitat Type
Temperate floodplain rivers and wetlands
Drainages flowing into
Most of the major rivers rise to the west of the Continental Divide and flow westward across the areas of uplift toward the Pacific Ocean (McPhail & Lindsey 1986).
Main rivers to other water bodies
The major river in this ecoregion is the
The Columbia River is the second largest river in the
The ecoregion is dominated by rugged mountain ranges separated by a series of lowlands and plateaus (McPhail & Lindsey 1986). Elevations range from 70 - 1,500 m (McNab & Avers 1994).
The ecoregion hosts a rich variety of freshwater habitats, including lakes, ponds, swamps and rivers. These unglaciated areas served as ice-free refuges for species during the Pleistocene period of glaciation (McPhail & Lindsey 1986).
Characteristic vegetation types in the ecoregion range from temperate coniferous forests to grasslands and shrub steppe (Ricketts et al. 1999).
Description of endemic fishes
The only endemic species within the ecoregion is the Oregon chub (Oregonichthys crameri).
The Columbia basin provides critical spawning grounds for anadromous fish, including numerous native salmon runs (chinook, coho, sockeye).
Justification for delineation
Ecoregion boundaries are taken from Abell et al. (2000) and are based on subregions defined by Maxwell et al. (1995).
- Frest, T. J.;Johannes, E. J. (1995). "Interior Columbia Basin mollusk species of special concern" Seattle, WA: Deixis.
- McPhail, J. D. and Lindsey, C. C. (1986). "Zoogeography of the freshwater fishes of Cascadia (the Columbia system and rivers north to the Stikine)" C. H. Hocutt and E. O. Wiley (Ed.) The zoogeography of North American freshwater fishes ( pp. 615-637 ) New York: John Wiley & Sons.
- Ricketts, T. H.,E. Dinerstein,D.M Olson;C.J. Loucks (1999). "Terrestrial ecoregions of North America: A conservation assessment" Washington, D.C.: World Wildlife Fund.
- Abell, R.,Olson, D.,Dinerstein, E.,Hurley, P. T.,Diggs, J. T.,Eichbaum, W.,Walters, S.,Wettengel, W.,Allnutt, T.,Loucks, C. J.;Hedao, P. (2000). "Freshwater ecoregions of North America" Washington, D.C.: Island Press.
- Maxwell, J. R., Edwards, C. J., Jensen, M. E., et al. (1995) \A hierarchical framework of aquatic ecological units in North America (Nearctic Zone)\ St. Paul, MN. North Central Forest Experiment Station, USDA Forest Service.
- McNab, H. and Avers, P. (1994) \Ecological Subregions of the United States: Section Descriptions\ Washington DC. U.S. Department of Agriculture, Forest Service.