Kenric - I found this campground in a campground book, and I tent camped there in July 2001 and July 2002.
The Lake Irwin campground is a great place to stay, if you want to stay near Crested Butte or to experience the mountain biking trails. The O'Neals keep the sites and the toilets very clean. There is well water at two stations. Many of the sites are along the lake and are decently spaced apart. The campground is also near the start point of the Dyke Trail. It's only a short 5-6 mile drive to Crested Butte to get supplies and access the rest of the trails.