Recreational Trails Program funds are apportioned to the States by legislative formula (23 U.S.C. 104(h)). FHWA receives $840,000 per year for program administration, trail related research and technical assistance, and training. The remainder of the funds are distributed to the States. Half of the funds are distributed equally among all States, and half are distributed in proportion to the estimated amount of nonhighway recreational fuel use in each State: fuel used for off-road recreation by snowmobiles, all-terrain vehicles, off-road motorcycles, and off-road light trucks. The estimates are based on a model developed by the Oak Ridge National Laboratory: http://www-cta.ornl.gov/cta/Publications/Publications_1999.html.