One-third of the country's land is publicly owned. President Barack Obama in a Friday proclamation for NPLD called for Americans to "rededicate ourselves to the important work of preserving and protecting our land and environment in our own time."
Nationwide, roughly 2,200 sites will host NPLD projects or events that include nature, recreation and clean-up efforts.
Though the National Parks Service offers free admission on several days throughout the year, the annual NPLD is the nation’s "largest single-day volunteer effort for public lands," according to The National Parks Conservation Association. Last year, volunteers supported the National Parks Service's various restoration, conservation and enhancement efforts by doing everything from scrubbing graffiti from rock faces to weeding invasive plants.
Volunteers who pitch in on NPLD can also get a voucher to visit any National Parks site for free during the next year. Below are just 14 stunning sites you can visit, chosen from among the nation's roughly 401 areas covered by the National Parks system.