The best trailhead for the hike is the Highline Trailhead located along State Highway 150 33.2 miles east and north of Kamas, or you could drive south from Evanston. You could also start at Mirror Lake, but you must pay to park there, and there isn't as much room to park.
This is a very direct route and it is short and steep
From the Highline Trailhead at Hayden Pass, follow the Highline Trail down
to the junction with the Mirror Lake Trail. Continue SE along the Highlline Trail. Soon you will reach the wilderness boundary. Continue along the trail for another .3 miles to a meadow. There are several variations possible for the next leg of the trip. You can leave the Highline Trail anywhere between this meadow and Scudder Lake (about .8 miles from the wilderness boundary). The next part of the route is easy to describe, but not as easy to do. There is no trail from here on, and you simply head east the base of the peak. There are many logs to cross, and many up and downs which don't show on the topo maps. You should hit the base right at or near Shale Lake. This is a small lake and makes a nice secluded campsite, though the route is very doable in a day. Look up the face. You will notice a rock outcrop. Head straight east for the outcrop. The next part of the route is very steep. The outcrop is halfway up the face, and the slope gets less steep up high. Just keep heading up the face to the summit. There are many teetering boulders, so be careful not to twist an ankle, especially when coming down. The total round trip distance from the trailhead is about 7 miles, but the going is pretty rough, so expect to take most of a day.
A good pair of boots is needed.