On peak summer days, thousands of hikers can be found along the extensive and diverse trail system in Acadia National Park. The collective use by so many visitors can take a toll on trail resources. Some visitors alter and build rock cairns; walk off-trail to avoid rocks, roots, and wet spots; and...

A wondrous display of synchronous fireflies at Great Smoky Mountains National Park draws many visitors to the park each spring. However, the small viewing area and limited number of days over which this natural event takes place challenges the National Park Service to prevent associated resource...