Odocoileus virginianus leucurus once ranged throughout the river valleys west of the Cascade mountains (USA). However by the 1940's conversion of land to agriculture and pressure from hunting has forced the deer into small vestiges of habitat where they are found today.
Two populations of the endangered Columbian white-tailed deer, which was listed as an endangered species in 1967, inhabit the Pacific Northwest of the US. One occurs in relatively dry lands in Douglas county, Oregon, and the other, known as the Columbia river population, is found in wet bottomlands and forest swamps of Washington and Oregon.
Both the Oregon and the Columbia river populations had declined sharply due to habitat loss and hunting. The population has since risen from fewer than 300 deer in 1940 to a current total of about 5,500.
Biologists now estimate a population of 60 deer on the Washington state mainland unit and 100 deer on 2,000-acre Tenasillahe island in the Columbia river. Before the onset of winter and the February 1996 flooding, deer populations were estimated at between 115 and 120 on the mainland and more than 200 on the Tenasillahe island. Most of the unaccounted for deer are presumed to have died. A separate population of Columbian white- tailed deer, estimated at 5,000 animals, is found along the Umpqua River in Douglas County, Oregon, near Roseburg.
Odocoileus virginianus leucurus is considered as "Lower Risk" sub-category "near threatened" by the IUCN Red List.