There's another friends group coming to the National Park System. This one is in support of Mammoth Cave National Park.

What do you get with 54 tons of concrete, 3,500 stainless steel bolts, and 35,000 pounds of structural steel? A new way to head toward the surface at Mammoth Cave National Park.

Long before anyone thought of national parks, folks were heading down into Mammoth Cave to see the sights. And if you've ever visited this incredible underground labyrinth, you'd understand why.

On a clear day, you often can see for miles and miles. But as a report from the National Parks Conservation Association points out, clear days are harder and harder to find in our national parks under the Bush administration's relatively laissez-faire approach to coal-fired power plants.

National Park Week is being celebrated this year from April 20 through April 26. Across the system there are dozens, if not hundreds, of special events planned. Here's a look at some of them.

Another nine miles of hiking and biking trails are coming to the national park system on December 8, when Mammoth Cave National Park dedicates the "Mammoth Cave Railroad Bike and Hike Trail."

One of the most intriguing interpretive tours I’ve joined across the national park system was the “wild cave tour” offered at Mammoth Cave National Park. For six or more hours in sections of the cave off-limits to the more traditional tours we scooted through tight places on our bellies when not able to get by on hands and knees.