I will list and describe the routes from the least technical to the most technical.
1. Trailhead: Trail Canyon - Class 1
Take Trail Canyon to the junction with the North Loop Trail. Head west (left) on the North Loop Trail approximately 4.4 miles to Photo 1 (36°17'7" N 115°41'23" W) below. You simply ascend the slope about 200 yards to the summit.
Photo 2 is a key landmark. Once past this overlook continue on the North Loop Trail approximately 200 yards to Photo 1. Look for the two odd trees with the red arrows in the photo. The cairn might not be there.
2. Trailhead: Trail Canyon - Class 3
3. Trailhead: Trail Canyon - Class 3
Take Trail Canyon to the junction with the North Loop Trail. Head west (left) on the North Loop Trail to the turnoff for Mummy Mtn. Ascend the scree slope veering west (left) about two-thirds of the way up aiming for a low point on the ridge. Follow the ridge to Lee Peak. There are hikers paths to follow and once you intersect the North Loop Trail for the second time the route is very well cairned. See Option 2.
4. Trailhead: Ski Lee parking area. - Class 3
This hike starts under the ski lifts and follows a gravel road to a small waterfall. From there it's bush whacking up a slope (there's almost 70 cairns to keep you on track) until the route drops into the drainage. Follow the drainage up to the North Ridge and head west along the ridge to the intersection of the North Loop Trail. The route now follows the ridge as in Option 2 above. This is the shortest, yet steepest route to Lee Peak. This route can also be used to hike to Charleston Peak. Once you intersect the North Loop Trail, follow it to the peak.
Note: Lee Peak is also called Ski Lee Peak