Discover the top 10 largest national parks in the U.S., dominated by Alaska's vast wilderness. Explore their unique ...

Yellowstone County Commissioners Jim Reno, left, John Ostlund, center right, and Bill Kennedy, right, are joined by MetraPark general manager Bill Dutcher, center left, during a ribbon cutting in ...

Last year, almost 400,000 vehicles entered Yellowstone from the north. On busy days, traffic is sometimes backed up from the park entrance across the bridge, about a half-mile away.

From arachnid-like formations and mysterious blobs to an underground ocean and a giant volcano, here are our 10 favorite ...

Among them were giant volcano sponges, Antarctic sunflower stars, and many other marine invertebrates. For now, the world’s largest invertebrate species frustratingly remains one of the animal ...

New photos from the European Space Agency's Mars Express orbiter give us our best look yet at a giant ravine on the Red ...