16 U.S.C. § 551a
The Secretary of Agriculture, in connection with the administration and regulation of the use and occupancy of the national forests and national grasslands, is authorized to cooperate with any State or political subdivision thereof, on lands which are within or part of any unit of the national forest system, in the enforcement or supervision of the laws or ordinances of a State or subdivision thereof. Such cooperation may include the reimbursement of a State or its subdivision for expenditures incurred in connection with activities on national forest system lands. This section shall not deprive any State or political subdivision thereof of its right to exercise civil and criminal jurisdiction, within or on lands which are a part of the national forest system.
16 U.S.C. § 551a