I ran into a situation in Montana in the 1990's with a tribal pronghorn hunt. I was hunting on private land, outside the Fort Belknap reservation on a friends private property. I ran into a tribal guide from the Fort Belknap reservation, outside the reservation boundary, but guiding/hunting a couple sections owned by the Fort Belknap reservation. The client wasn't wearing orange and was hunting under a tag issued by Fort Belknap.
I always wondered about the legality of that?
I’m not familiar with the Fort Belknap treaty, but typically any fee land outside of the reservation is subject to state laws and regulations, particularly if a non tribal members is involved.
However, this is the same tribe that tried to arrest a state game warden on a county road, so WTF knows?