25 CFR 170.106 - When must State governments consult with tribes?
Each State must develop the State Transportation Improvement Program (STIP) in consultation with tribes and BIA in those areas under Indian tribal jurisdiction. This includes providing for a fully coordinated transportation planning process that coordinates transportation planning efforts carried out by the State with transportation planning efforts carried out by tribes. The statewide and metropolitan planning organization requirements are in 23 U.S.C. 134 and 135. Regulations can be found at 23 CFR part 450.