Dispersed Camping at American Lakes
This is one of my all-time favorite places to hike and camp in Colorado. I have not yet stayed in any of the campgrounds but have backpacked to the top of the American Lakes Trail. Not only is this hike fantasticly beautiful and full of wildlife (tons of moose especially) but there is great dispersed camping along the trails. You simply cannot find more scenic and free camping in Colorado. I would highly recommended camping anywhere in State Forest State Park!
Also, there are quite a few huts, cabins and yurts that can be rented year round in SFSP!