Whistler Mountain is one of the many peaks on the North Cascade Highway. Located between the Rainy Pass parking and Washington Pass Lookout parking area. Greater attention is given to Cutthroat Peak for climbing and height, but the two are joined by a common ridge. I can only find this climb in the Beckey book, page 353, with a very short climbing description sufficient for this mountain. Its another great climb for monderate ratings, class 3 and 4, but you could really play around here if you are looking for conditioning, practice and magnificient views with a short approach.
Directions from the west side. Drive the North Cascade Highway to a very wide section of the Highway just short of the Blue Lake Trail (also the Liberty Bell trail). You can see the brown sign from where you park on the side of Highway. There is a double paved shoulder area here. The upper meadow and climber's trail is visible from car. It is the same approach to Cutthroat Peak.
Since the wide turn out is not a trail head, I do not belive a Trail Pass is neccessary here. If you park at the Blue Lake Trail where climbers start for the Liberty Bell group and walk back (why would you), then a Permit is required. I included a photo of where we and others park to help you make this decision. Parking on the side of the road here is no problem. The nearest Ranger station for permits and info is at Marblemount on the west side of the passes. 360 873-4500.
There are numerous campgrounds on both sides of Washington and Rainy Pass. The first campground east of the Passes is Lone Fir. The town of Winthrop is east about 25 miles. No formal camping at the Passes is permited, but many of us have slept a short night in our vehicles at the Blue Lake Trail parking which is less than one half mile from the turn out where the climbers trail begins for Whistler and Cutthroat.