Base Campground is at the end of the road from behind the FS campground at the East Summit of Rabbit Ears. Turn right about a mile after the East Summit. Theres decent camping along this road all the way to near the end. Great mountain biking from there to Fish Creek Reservoir and Buff Pass.
You can try the few spots just to the north of the old summit, where the original monument is. These may now be closed...
Also try Buffalo Park road, just a bit closer to the East Summit, on the south side.
Theres another road that goes to Walton Peak on the south side, about halfway across Rabbit Ears. No signage, but its in a big meadow and hard to miss.
Ive also camped out off a side road on the south side of Gore Pass, a turnoff just north of Kremmling at Wolford Mtn Reservoir, and connects to the Toponas/Oak Creek area.
Dont need no stinkin' campground. Enjoy.