[1] Although there are variable reports, some sources report that there are four species of mammals found exclusively in Oregon: the Baird's shrew, the Pacific shrew, the camas pocket gopher, and the red tree vole (North Oregon Coast "distinct population segment").
Most of these are smaller creatures weighing under one kilogram, active primarily at night, with a tendency towards more inconspicuous ways of life.
[4] Elk were heavily hunted in Oregon in the 1800s leading to their extirpation from all but the most inaccessible parts of the Blue Mountains.
[5] The gray wolf was extirpated from Oregon in 1947 and returned in 1999 when wolves from Idaho began to move into the state.
[5] The gray wolf populations has been increasing in recent years and is monitored by the Oregon Department of Fish and Wildlife.