Very beautiful mountains. It takes a day to drive around if you don't plan to hike a lot. Shouldn't miss it if you plan to go to Yellowstone. For the time and money investment, the return is extremely high.
If you want to take good pictures, go here in the morning as the mountain is at west of the river...
All I can say is this place is absolutely awesome, and it wasn't as crowded as I thought it would be. There are great hiking trails. There was a lot of wildlife closely observed. The scenery was remarkable and breathtaking. I can't wait to revisit this place.