There is an RV park in Virginia City if you want to stay right in town. Haven't stayed there, but have seen it. IMHO, it only takes a couple of hours to see all the "tourist sights" in Virginia City, so you may want to just stop, visit, and continue on your way between Glacier NP and West Yellowstone.
There are also a couple of very small, but shady RV oarks in Ennis, if you just want to leave the RV at one of them, drive over to Virginia City, visit for the day, and drive back. That way you could just stay on US 287 to continue your trip. Take a look at RVParkReviews.com for more info on the Ennis RV parks.
I highly recommend stopping at the Earthquake Lake Visitor's Center on US 287 44 miles south of Ennis. In case you don't have a personal memory of the event, Quake Lake was formed by the August 1959 Hebgen Lake Earthquake. A Forest Service campground in the Madison River Canyon was buried by a landslide, killing 21 people and trapping another 300. A geologist I worked with was doing field work nearby and experienced the quake first-hand.
"Retirement is the best job I ever had!"
2015 RAM 2500 4x4 crewcab 6.7L CTD; 2016 Rockwood Signature UltraLite 5th wheel