This location offers some full hook-up locations, but they are generally pretty tight and some are fairly uneven. 

The people running the KOA are nice and accommodating (We had to change spots because we felt that we could not safely level our trailer due to the site eroding on the low hill side- YIKES!) The cell service was good.

This is about 15 minutes from the West Yellowstone Gate and outside the town of West Yellowstone by roughly the same. We went in their last week of operation before they closed down for the season and it was... sparse. I'm sure during the summer it is much more lively and fun to be there. 

To be truthful, we would maybe stay here again, but would MUCH prefer to stay in the park, even if we didn't have full hookups.