Oklahoma Three Corners Trail is a 1.5 mile lightly trafficked out and back trail located near Folsom, Oklahoma and is good for all skill levels. The trail is primarily used for hiking and walking and is accessible from March until November.
You can drive it or walk it, the trail is clear but not well marked. Near Oklahoma's Black Mesa trail, but you have to drive into Colorado to access it from this point. Not much to see, just a chance to walk out in the wide open to a minor point of interest. But if you're in the neighborhood, do it. Its on federal land.