Your fourth grader is your family's free pass to the nation's national parks.

Starting Sept. 1, the federal government is giving annual passes to fourth graders and their families, an effort to get kids into the national park system to experience the outdoors and learn a little history and culture. Families without a fourth grader must pay $80 for the annual pass, unless the family includes a senior citizen or member of the military.

To get your free pass, go to http://www.everykidinapark.gov and have your fourth grader answer a few fun questions about outdoor adventures. After that, you'll get a paper pass that you can print out and use — or trade in for a plastic annual pass that is the size of a credit card.

Even if your kid isn't a natural outdoors enthusiast, being part of the “Every Kid in a Park” initiative can be a fun and easy activity for the whole family, especially if you do a little research.

Need some more help figuring out where to go? Sign up at http://www.nationalparks.org and you'll get a free guide with 35 parks adventures for kids. Or just stop by the park's information desk and ask a ranger for suggestions on age-appropriate activities or hikes.

Still worried your kid may not be excited about walking wooded trails or studying Native American ruins? Here are a few ideas to get them engaged:

NATIONAL PARKS PASSPORT: Most national park gift shops have Passports to Your National Parks. They're books that look like real passports and offer travel tips for different regions. They also allow kids to gather stamps from each place they visit.

JUNIOR RANGER PROGRAMS: Most parks have a junior ranger program that encourages kids to become outdoor stewards. The program varies slightly at each park. Sometimes, kids get a free booklet filled with activities or worksheets on spotting local wildlife. You can download booklets at http://www.nps.gov/kids/jrRangers.cfm.