Portions of this trail, especially if you're exploring, can get overgrown and make for a poor run.
The Group 63 Interim Trail is a 3.6 mile dirt road that loops around the Group 63 Ammunition Bunkers. While the trail itself isn't spectacular, the grass-and-tree-covered mounds it surrounds are. Most of the bunkers are sealed, but visitors will enjoy nosing around the area and exploring these relics of a bygone era at their leisure.
Make sure to check out the open Group 63-1 Bunker on the eastern side of the loop near the intersection with the Group 63 Connector
Keep your eyes peeled for bison along the southern side of the loop.