From the Talache-Blacktail Trailhead, take the trail northeast out of the parking area. The trail immediately starts gaining elevation and it steep and rocky in places. The first mile is mostly switchbacks while you are shrouded in trees. Views start to open up after about three-quarters of a mile. The trail has recently been rerouted and intersects the old trail in several places. If the correct trail is not obvious, always choose the less steep option and that will keep you on the newer reroute.
After a mile, the switchbacks lessen, but the trail gets steeper for the next mile. At two miles, you will reach a saddle where the trail splits. It's highly recommended to make the short side detour on the right fork for a quick visit to Blacktail Mountain. The left fork at the saddle continues north to Butler Mountain.
The next three-quarters of a mile is relatively flat as the trail heads north up to Butler. The summit isn't obvious, but you can tell when you seem to reach the highest point of the ridge. The summit is in a meadow, and heading left (west) off the trail for about thirty feet to the highest spot is basically the summit. There were several rocks painted yellow that seemed to be marking the summit--my guess is that it was an old cairn that has been knocked over. There are not many places to sit, and views are limited due to being surrounded by trees ringing the meadow.
Once done, retrace your steps back down to the trailhead. The hike back down goes by quickly but is steep, and rocky in several places.
Check out the Official Route and Triplog.