You can hike to Glacier Campground, but it's nowhere near a shuttle. Backs up to the corner of RMNP, but it's a back road to get there. Better to drive into the park and park at the shuttle parking if you can, if the hike is too much.

This campground is at the end of a road that leads out of Estes Park to the East Portal of a water project tunnel. There’s a lake there that has fishing available. As far as I know, there is no park shuttle that comes to this site and it is not listed on the website for the campground. If you’re a good hiker, you can actually take a trail from the campground into Rocky Mountain National Park.