|The 105,460-acre Wenas Wildlife Area, southwest of Ellensburg in both Yakima and Kittitas counties, is managed as one unit.
WDFW owns 70,093 acres, leases 16,514 acres of the 30,643 acres owned by DNR, and manages 3,485 acres for BLM. Elevation ranges from 1,200 to 4,100 feet. Much of the land is very dry, with predominantly south-facing slopes. Except for the cliffs along Umtanum Creek and the Yakima River, most of the topography is not overly steep. The unique soil formation known as the Manastash Mounds is found throughout lands lying south of Umtanum Ridge.
Property was first acquired in the mid-1960s for elk wintering habitat. A winter feeding program is conducted annually to help meet management goals for the Yakima elk herd.
The northwest portion is drained by Wenas Creek, with several smaller tributaries flowing southwest to northeast. Numerous perennial springs are scattered throughout, although water is not well dispersed over the northern exposure of the South Umtanum Ridge. Umtanum Creek runs for ten miles through the wildlife area before emptying into the Yakima River. Steep basaltic cliffs rise on both sides of the stream corridor. The narrow riparian forest zone adjacent to Umtanum Creek is comprised of ponderosa pine, Douglas fir, black cottonwood, aspen and willows. Beaver are active in this drainage. Roza Creek flows about four miles in a southeasterly direction into the Yakima River. Bordered by steep slopes and ridges on both sides, the creek bottom supports a narrow band of riparian shrub/forest habitat throughout its length. Beginning in the mid-1990s, beaver moved into the drainage and have constructed multiple dams on the creek resulting in raising the water table and reducing water velocity. All of these streams are fish-bearing and some, notably Umtanum, historically supported anadromous fish that are currently federally listed, including steelhead. WDFW and other state and federal agencies are actively pursuing the removal of barriers from these streams to re-establish anadromous fish use.
Much of the Wenas Wildlife Area is dominated by shrub-steppe vegetation. Some forest vegetation types exist at higher elevations and in riparian areas.
Wildlife use is diverse, including elk, deer, bighorn sheep, sage grouse, turkey, quail, and a myriad of small mammals, neo-tropical/upland birds, raptors, and reptiles. Big game hunting is popular.