Yellowstone National Park rangers are looking into the story of a Utah man who cross-country skied into the park in November, allegedly armed with a Glock 9mm. The man appears to have camped alongside the Madison River outside of designated campgrounds. He also found some time to enjoy the warm waters of hot springs near Madison Junction, something that also is against park regs.

Great gray owls are not only an endangered species, they're also the largest North American owl. Yosemite National Park is home to about 75% of California's population of these impressive birds, and new research suggests they're even more unique that previously believed.

Cape Hatteras and the Outer Banks of North Carolina have long been known as the "Graveyard of the Atlantic," and among the more than 1,000 vessels believed to have been lost in the area are some from World Wars I and II. They'll be the subject of a talk near the park on January 20.

Volcanic activity and volcanic landscapes are the centerpiece attractions of this unique park on Hawaii’s Big Island. Here are some things to know before you go.