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.