Book excerpt: This publication presents a national study of outdoor recreation trends as part of the 2010 Renewable Resources Planning Act Assessment by the Forest Service, U S Department of Agriculture The objectives are to review past trends in outdoor recreation participation by Americans, to describe in detail current outdoor recreation participation patterns, and to compare patterns across regional and demographic strata Further objectives include describing recreation activity participation on public and private lands and providing projections of outdoor recreation participation out to the year 2060 One overriding national trend is quite evident: the mix of outdoor activities chosen by Americans and the relative popularity of activities overall have been evolving over the last several decades One general category of activity that has been showing growth in the first decade of the 21st century is nature-based recreation Between 2000 and 2009, the number of people who participated in nature-based outdoor recreation grew by 71 percent and the number of activity days grew about 40 percent