Buck Mountain is a summit with a short hike of less than half a mile that you'll want to do along with Coffin Mountain (W7O/WV-005) and Bachelor Mountain (W7O/WV-003).

Take Highway 22 east 19 miles past Detroit, Oregon and turn right onto paved FS 11. Stay on this road for about 4.2 miles then turn right on road #1168.

You'll find the trailhead near 44.60451, -122.04061 - there's a wide spot for parking just past that. This is about 0.7 miles from the Coffin Mountain trailhead - marked with a red dot on the map below.

You'll take the ramp up to the abandoned road which eventually is quite passable after the initial berms. You'll be in the Activation Zone after you turn the west corner. But from here you can make the summit proper if you like - see the detail by Roger-ND7PA here: http://www.pnwsota.org/blog/nd7pa/2014-december-07/coffin-and-buck-mountain-1262014.