Sharing a Secret (IMAGE) USDA Forest Service - Northern Research Station Caption Americans began heading outdoors enmasse 60 years ago, and the magic has endured. Forest Service research suggests that in 20 northern states, the growth in both the population and popularity of outdoor recreation's will likely create pressure for available state and federal recreation areas. Credit US Forest Service Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.