INDIANAPOLIS (AP) — Admission to most Indiana’s State Parks and State Forest recreation areas where entrance fees otherwise are charged will be free on Sept. 22 in recognition of National Public Lands Day.

Spring Mill State Park will offer the free admission on Sept. 23.

National Public Lands Day is the nation’s largest single-day volunteer effort for public lands.

Volunteer opportunities include trail work at Clifty Falls State Park, seed collecting at Prophetstown State Park, invasive plant removals at Charlestown, Chain O’Lakes and Fort Harrison state parks, and cleanups at Mounds and Summit Lake state parks.

Properties also will offer hikes, pioneer activities, crafts and live bird shows.

A complete list of programs is online .