Buck Mountain Loop Professional Review and Guide
"This short but immensely rewarding side trip off S.R. 20 takes you to a 6,135-foot peak on the eastern slope of the Cascade Range. The views of the region where Washington’s dry eastern expanse meets the forested mountains is outstanding. But of course, as with all lookout sites, the best views are from the summit, where the state maintains a 20-foot-tall lookout for emergency use. Unfortunately, access to the tower, built in 1961, is restricted to Washington Department of Natural Resources personnel.
This is an easy-to-moderate 4WD route, although it becomes fairly rough, steep and narrow along the final 1.5 miles or so. I recommend using low-range 4WD. There is one tight switchback that you may have to take in two moves."