Yellowstones EdgeWe stayed @ the above CG about 30 miles to the North Entrance. Picked this because I'm not fond of steep grades and although a lot of folks say it's no problem I wasn't so sure. I'm the route planner. Now that we've stayed here - my husband said I made the right choice. He said if we returned he'd be ok with Grizzly RV park but the others -they are just not big enough or not enough services and too much work to get there. He prefers to find a nice comfortable place to stay make the trek to our daily destinations in our Jeep.
If doing early in the year they say get your trip in before Mid July - after that the peak tourist season kicks in and traffic will be heavy.
If you choose Yellowstones Edge - request a site on the North end - near the river instead of the road. Stay away from the South end sites that backup along the river. The flying bugs from the river are heavy there. But the other side is really nice and better views. Some nice restaurants not too far from the CG. A general store (that stocks more than a convenient store and gas station also about 4 miles away.
Here's a great article on Yellowstone and driving recommendations from thru all entrances.
http://www.rvtechmag.com/travel/4_yellowstonebyrv.php?pg=allHere's another great resource on mountain driving when off the interstate.
http://www.mountaindirectory.com/coverage-area-west/ You probably know the grades on interstate are typically no more than 7%.. exception in a few areas. Because I do not feel like Magellan.. I keep us on the interstates in the MH. :-)