1700 is an out-and-back trail running 13 miles south of West Yellowstone along the western edge of Yellowstone National Park. The northern half has about a dozen campsites, all easy to access from the road. Most sites are suitable for one or two vehicles, with a larger one farther south that's perfect for a big group.
Near the southern end of the trail is the Yellowstone Obsidian Outcrop, a neat little geological spot.
About two-thirds down the trail, at the western end of the only meadow this trail overlooks, you'll find Whitman's Cabin. There isn't any info on this place besides a mention on a 1960s topo map.
Overall, 1700 is an easy trail for those looking for camping access, cool geology, and a touch of history.