If you’re going to an organized camp Group there are a few around Lake Dillon.
I have no personal experience with any of these; we typically do not camp in Summit because we have a condo there.
Heaton Bay: the best sites are in Loop B, 18, 19, 21, 22, 23 and Loop D 48, 49, 52, 44, 43 this according to a guide book.
970-468-5400 this number is listed for all Reservations
Peak One Campground
If you want to camp in National Forest but close to town. you can go to the West Frisco/Main street exit off Hwy 70. There is a trailhead parking area immediately to your right. You will have to hike about 1 mile to National Forest. Pretty nice along the river. This trail is busy though not as busy as the campgrounds.