Signal Mountain or Gros Ventre Campground?

Another option in the GTNP is Flagg Ranch now called Headwaters. They have a campground with hookups. I've heard good and bad and have stayed there and it was fine for us. We've also stayed further away at Baker's Hole NFS CG 2 mies north of West Yellowstone. Most sites have electricity and there is a water fill station as you enter. Another place we've stayed is off the Togwotee Pass at Falls NFS CG. One loop has electricity and longer, wider sites for RV's. It's a bit of a drive but still do-able.