I' ll elaborate a bit on huntingthewild' s post: Contact the USFS/BLM in that area first. they have regional maps that very clearly designate lands by type. i.e Private, USFS, BLM, Wilderness under various jurisdictions and also by motorized access and road type. These maps also show seasonal motorized access. They however have no topographical or other terrain type illustration (slope, elevations, water, vegetation, etc) and are best used in conjunction with a good topo map of the same area. (This also often presents contradictions between the two map types and can give you questions to present the governing authority of certain lands, trails and roads)