Lake Umatilla and Lake Wallula share the southern border of this unit along the Washington and Oregon border. As you make your way on a big horseshoe bend going up the Columbia River, you will reach the tri-state region, with the Yakima River serving as the northern border, to Mabton, where the boundary cuts south over land forming a sharp western point. This unit is all private except a few small pieces of BLM, state and Umatilla National Wildlife Refuge across the river from Irrigon and Boardman, Oregon. Horse Heaven Hills is the only dominant land structure here and arches over the northern border with urban sprawl on the eastern side of the hills. Just about every inch of dirt inside the Horse Heaven Hills has been tilled for agriculture, the northern area has dryland farming with the southern portion predominately irrigated. Rocky Mountain Elk, mule deer and whitetail deer success usually depend upon private land access. The WDGF is working on expanding access and has both Feel Free to Hunt and Hunt by Written Permission signed up for some private land access. Multiple small to medium fires have dotted this landscape over the past decade and most common along the dry grasslands north and west.

Private land access is extremely tough to find and expensive when you do.