A new national program encourages families and classes to visit national parks by allowing 4th grade students to obtain free annual passes to more than 2,000 federal recreation areas, including national parks, monuments and historical sites.

From Sept. 1, 2015 through Aug. 31, 2016, 4th grade students can visit www.everykidinapark.com and play a game to access their Every Kid in a Park annual pass. They can then use the pass to treat their families to thousands of parks and sites across the country at no charge. The website also includes learning activities, safety tips, and trip-planning tool...