What a weird corner, but I might be tempted. There's a similar spot near the CO/WY border that I wanted to use to access our CO unit at the time, but there's a road in this spot. I went to scout it and there was a lock on the gate saying it was a private road, but that land was marked BLM on all the maps.
Ok. Long ago and far away. 1978.
Four of us put in for antelope tags in Wyoming.
We immediately acquired maps of our antelope area. Huge areas of Nat'l Forest (?) and BLM land.
Everything we read and understood was that all those lands were open to public hunting.
BUT.....when we got there, a ranching outfit that had leased the grazing rights on the BLM lands let us know we couldn't hunt there!
Within five minutes, we ran into a DOW officer and asked him.
He told us the grazers were wrong, but it would be best if we just stayed away from their grazing areas.
No biggie, there were antelope EVERYWHERE and all four of us scored. We actually killed our antelope on the Stroecker Ranch. He was more than happy to have hunters get rid of some of the antelope!
NOTE #2
The Southern Ute Indian Reservation near Pagosa Springs, CO put "Posted" signs on gates that led to roads crossing the reservation to public land.
It IS NOT common knowledge that the tribal police can't keep you from using their roads to access public property.
Once we found that tidbit of information, we found several little nooks and crannies that we could hunt almost undisturbed!