It's long been said that you should take only photographs and leave only footprints when you visit a national park. Well, a dispute over whether Native Americans can legally collect plants in the parks has prompted a group to call for a federal investigation into whether the National Park Service is looking the other way.

Wildlife experts have no solid explanation for why a grizzly sow and her three cubs rampaged through a campground outside Yellowstone National Park late last month, attacking two campers before killing and partially consuming a third.

Restoration work on the Boulder Creek Trail in Olympic National Park has necessitated the closure of the trail, as well as the upper Hot Springs Road, to the public through the fall, according to park officials.

In honor of the 94th birthday of the National Park Service, officials at Mammoth Cave National Park are offering free tours of the Mammoth Passage cave on August 25.