National Parks For Free (Saturday Only!)

Saturday marks National Public Lands Day, the largest, single-day volunteer event for public lands in the United States. In honor of NPLD, all national parks will be free for the public.

While you can spend this day hiking, climbing or paddling through the wilderness, you might also consider outdoor volunteer opportunities across the country. This year more than 170,000 volunteers are expected at more than 2,100 sites. It's a great chance to meet other outdoor-lovers and give back to the places you love to play.

At NPLD 2011, volunteers collected more than 23,000 pounds of invasive plants, built or maintained 1,500 miles of trails, removed 500 tons of trash and planted 100,000 trees, shrubs and other native plans. Their contributions added up to an estimated $17 million in volunteer services.

The event honors the Civilian Conservation Corps or "tree army" that worked from 1933- 1942 to preserve America's natural heritage.

Via Gadling.