... In June, 2011 the U.S. Department of Interior (DOI) produced a report on their economic contributions and, among other things, provided current information on park visitation and the economic ... mentioned in the report section on nature conservation as well. Additionally, the ripple effect greatly increases the economic contribution of fish and wildlife-based recreation on NFS lands. ... to the national level, the results were even larger. The effects of the visits on the national economy were $34.0 billion in sales, contributing $17.1 billion in direct income and supporting...