Ponderosa pine dominates the lower drainages, then defers to a forest of lodgepole pine above about 4,500 feet, with some larch, fir, and spruce. Subalpine fir reigns supreme at the highest elevations, with grasses covering the ground. Large herds of Rocky Mountain elk thrive in this area, which subsequently attracts more hunters than hikers. Rattlesnakes love the area, too, and you may see mule deer, white-tailed deer, black bears, coyotes, cougars, bobcats, marmots, and snowshoe hares. Snow falls and accumulates about two feet deep between November and April.
Summers are typically very hot and very dry.
Most of a fairly extensive trail system stays high on the open ridges, winding and connecting often enough to provide long loops through the Washington side and down into Oregon. Several trailheads are equipped for easy unloading and loading of horses. Backpacking has increased in popularity here, especially in summer and early fall, on more than 200 miles of maintained trails.