Sovereign nations, they have their own laws
Their laws commonly mimic state and federal laws, but each tribe has its own unique things.
If you are on state-owned highways, you should/might be OK, but once you are on land owned by the tribe, you will probably be denied your 2A rights under their laws.
For instance on the unique laws, in this entire country an employer cannot legally discriminate on race, but in LDF, they have a hiring/promotion priority for natives, It does not matter if you are perfectly qualified for the job you are applying for, if some know-nothing shows up, and he is native, they will get hired before you even though they are not qualified to do the job they are hired to perform.