See the Getting There section of the main page for directions to the trailhead.
Take the trail from road's end up the old road about a mile or so (being turned into new trail), it will eventually head left into the forest when you come to the last grassy, mossy camping area. This area was a 1972 clearcut according to Sullivan's book.
Head up through old growth forests to a viewpoint at 1.4 miles from where the road trail ends and the old TH was heading into the forest and about 2800 feet. The route continues up forested slopes (ignore a trail that heads to a clearing at a switchback, there are no views anyway). About 4200 feet you will finally make the top of the ridge and flip over to the other side. It is about 2.4 miles from the viewpoint to where the trail ends at an old abandoned road, little more than a wide dirt path now. Turn right at the road and go .6 miles to the summit spiraling around to the right. (If you want to explore the craggy southeast arm of Salmon Butte, turn left on the road, go a short distance and climb up onto the ridge when you come to some rocks.)
Descend the same trail. Total distance is about 5.4 miles one way with around 3000 feet of elevation gain.
If you have information about this route that doesn't pertain to any of the other sections, please add it here.