I live in CO and have recently bought the Colorado Hunting Map from "Hunting GPS Maps". I loaded it on a Garmin Montana and love it. You always know the legal status of the land around you; BLM, N. Forest, private, etc. It even shows the owners name for private land.
For anyone hunting/hiking/shooting public lands it important to know where the boundaries are. Once we started carrying it we found in years past we had crossed private in places and places where land owners wrongly blocked access. I have no experience in other states but in CO there are little chunks of private land surrounded by public land, old 'improved mining claims, homesteads, etc where physical boundaries aren't obvious.
Jack