Gov. Bill Ritter signed a bill that tightens the rules for off-road vehicles that allows 250 state officers to enforce laws on federal lands.
The new law prohibits motor vehicles from using public lands, trails, or roads unless it's authorized by a sign or other means.
Violations in designated wilderness areas would carry a $200 fine.
Supporters defeated and amendment that would have made the trails open to use unless they are specifically closed. Instead, people will be given maps to tell them which ones are open, or they could check the signs.
Opponents argued it's wrong to use state funds to enforce laws for the federal government.