Nearly the entire mountain to the south of the official Soapstone campground is open to dispersed camping. There are several dirt roads (best accessed with SUV's or Trucks) that wind around the mountain top, in and out of trees and meadows. Nearly every few hundred yards there are different pull-offs where you can just set up camp. There are obviously no water hookups or vault toilets, so pack-in, pack-out.
The area is pretty busy during the summer months, and even busier during holiday weekends (Memorial Day, 4th of July Weekend, 24th of July Weekend, etc.). You'll also likely see deer and even moose wandering around your campground in the early morning and late evening. So, if you want a close getaway to do some "rough-it" camping, this is your spot!