We did a small backpacking trip from the Greendale Overlook on highway 40 to the Canyon Rim campground for the night. The hike was beautiful, crossing creeks and surrounded by ponderosa pines. It's about 4.5 miles one way.
Canyon Rim Campground is beautiful, also surrounded by ponderosa and aspen, and with a beautiful overlook of Flaming Gorge Reservoir. There are specific sites for tent camping, and plenty of RV spots. Each spot has tables and fire rings. There are vault toilets.
Our only complaint is that all of the water to the campground was shut off! No signs warning that there was no water available. This was actually awful as we had backpacked in with our dogs (who at this point were very thirsty), and brought dehydrated food that required water to make. Luckily, Red Canyon Lodge is located about a mile away. We were able to hike over and buy water. 16 small bottles of water for like 45 dollars...not ideal.