Pataha Bunchgrass Research Natural Area Umatilla National Forest , USFS Blue Mountains, Washington Ecoregion Cell(s): Bluebunch wheatgrass-Idaho fescue Douglas fir-ponderosa pine/pinegrass Grand fir-Douglas fir/big huckleberry

Access by road

The Pataha Bunchgrass RNA is located in Garfield County, Washington. The 20.7 ha tract has a mean elevation of 1,372 m with a total variation of 60 m, and topography varies from flat to steep. The natural area is located on the edge of a dissected plateau straddling the transition from the flat plateau top to steep canyon slopes. South slopes of the RNA represent an upper elevational extension of the bunchgrass steppe, and north slopes represent a lower elevational extension of true fir forest. Bluebunch wheatgrass (Pseudoroegneria spicata) dominates the bunchgrass stands, and on the plateau it is associated with Idaho fescue (Festuca idahoensis) and Sandberg bluegrass (Poa secunda). On the transition from plateau to steep slopes, bluebunch wheatgrass co-dominates with Sandberg bluegrass. The 7 forested hectares are dominated by Douglas fir (Pseudotsuga menziesii) with occasional ponderosa pine (Pinus ponderosa). The understory is dominated by Vaccinium membranaceum and pinegrass (Calamagrostis rubescens). Ponderosa pine, exhibiting an open growth form with living branches within 3 m of the ground, dominates an interrupted transitional band between grassland and Douglas fir forest. The understory is dominated by pinegrass; associated species include elk sedge (Carex garberi), Spirea lucida, Lupinus latifolius, and Achillea millefolium. The lack of dominant old-growth grand fir in the Pseudotsuga-Abies/Vaccinium community and downed western larch (Larix occidentalis) suggests that the entire area has burned at some time. The last fire is believed to have occurred around 1890.