Mount Powell is a cool peak in the Gore Range that does not see many ascents, mostly due to its remoteness. You could do this peak in one day, but I definately recommend an overnighter unless you are a total badass. The route is given in Colorado's High Thirteeners, but I will add some things I found:

When you hike in, the turn off for Mount Powell is right where they say, and you can tell you've gone too far when you hit a tricky stream crossing a few hundred feet past the left hand turn off. Just past this stream crossing is a great camping spot on the right side of the trail. This is a nice place to make camp, if you want to summit the next day, break camp and hike out. An alternative is to head up the Mount Powell branch with your packs (steep) and fight along the narrow trail until you reach a high altitude meadow literally at the base of the mountain. There is a stream and some great campsites here. The advantage is the summit attempt will be much easier the following day, but you'll have to schlep your packs up and down a difficult part of the hike. The high altitude meadow is awesome for wildflowers if you go late enough in the summer (mid-July or later).

To summit, hike directly up a STEEP trail to a pass, trun right and follow the ridge 1/4 mile to another pass, and then turn left for a third class fun scramble to the summit.