sentences:  Trees include primarily Sitka spruce, western redcedar, Douglas-fir, and western hemlock.Other plants include huckleberry, salmonberry, salal, vine maple, Oregon grape, bracken fern, and thimble-berry among others.The northern boundary is the Columbia River, with some mountainous features on the north side of the river, and continues south for approximately to the Salmon River where Oregon Route 18 crosses the range from the Willamette Valley to the Oregon Coast with width roughly .