We stayed in site 12, which was rated as an RV campsite, it was pull through, but the hosts said mainly they use that area of the campground for tents with the RVs across the street (RV sites 1 - 9).  If you are tent camping, the upper sites are really nice and secluded (20s - 30s).  RVs cannot make it to sites 20s - 30s because it is a narrow dirt road to the top.

It's dry camping - no RV hookups, but at the visitor's center they have a water fill station that is free.  You can pull in and fill up your RV water tank.  There is no dump station at the park, nor in Glendive, so you have to drive to Miles City or Wibaux to dump.  We found a Cenex in Miles City that had a good dump station and it was free.

The sites were spacious, clean and affordable.  Sites 11 & 13 had a nice view.  The bathrooms were pit toilets.  Very clean.  No running water.  Camp fires are permitted.

The camp hosts were really helpful and friendly.

We spent one day in Makoshika hiking the trails with our dog.  We felt that 1 day was sufficient, but you could easily spend more time to enjoy the park, take some longer hikes, or play disc golf.  The other day we took a drive to North Dakota to check out Theodore Roosevelt National Park, about an hour drive away.  Well worth the drive.  We stopped at Beaver Creek Brewery on the way back to the campsite and brought back a growler for around the campfire.

They said next year they plan on expanding the campsites and adding in some full hook-up RV sites and a dump station.  Even without that, we plan on coming back.

I'd book in advance if you are planning on going over a weekend.  The campsites were all booked when we arrived.  We reserved our spot about 3 weeks prior.