 The Keep Colorado Wild passes attached to drivers' annual registration seems to be working. Colorado Sun says 1.5 million vehicle owners added the $29 license plate fee to get the pass, and in turn over $40 million was raised for avalanche forecasting, search and rescue groups, and Colorado Parks and Wildlife. Drivers can opt out of the added fee, which 70% of drivers did, but the pass add-on gets access to all state parks.