Stayed 4 nights at Canyon Campground tent only loop B. We used it as a base to explore the park. Most other tent campers only stay 1 or 2 nights. While this is definitely the cheapest way to stay inside the park there are some MAJOR cons.

1. All the sites are right on top of each other and there is no privacy at all.
2. Loop B (where they seem to stick single small-medium tents) is literally off the registration/laundry/shower/Recycling/garbage/dump station. (Read more below about specific sights in loop B)
3. Because it’s Yellowstone all types come here—including people who have absolutely no clue about camp etiquette. (We were woken up two of the four nights because two different people in the loop behind us decided to use their car lights to set up or (no clue what the others were doing) their sites—we’re talking 1 am car lights shining directly into the tents or ignoring rules about locking all food related items (containers and grills) away when not in use.
4. Related—Guests can check in whenever—like at 1 am
5. You’re right off the exit of North Rim Drive. (Some of the sights in loop b back up to the road). It is heavily traveled. Also there are rivets in the road to warn people to stop near by—at about 6 am you wake up to construction crews, workers, and guests driving over them.

The positives: restrooms were clean, but by the first week of September half of them were closed despite the loop being full.

LOOP B SITES to avoid: 31, 32, 33, 34. These literally overlook the RV parking lot for the registration/garbage facilities. (Pics below)