We go to national parks to admire nature at its finest, often with hopes of catching wildlife in action. Few of us ever do, outside of grazing deer, elk or bison, or coyotes or even wolves in the distance, or black bears on the hunt for a free handout wrapped in a cooler or unlocked car.

But nature very much is constantly in motion; unwitnessed, more often than not. I came upon such evidence during a January trip to Yellowstone National Park when I found the paw prints of a wolf on snow flecked with bits of fur and blood from its intended meal.

As the accompanying photos show, nature can be cruel, and it can be a great equalizer for predator and prey. That was the case earlier this year in Glacier National Park, where an apparent avalanche swept an attacking mountain lion and its bighorn sheep prey to their deaths.

In an episode that might have been pulled from a Jack London novel, the lion obviously seized a bighorn sheep with its powerful mouth, only to be killed, along with its catch, in a tremendous fall from a cliff down onto the Going-to-the-Sun Road on the east side of the park. The deadly event occurred early this past spring, before the road was open to traffic, and the resulting death scene spotted by one of the park's road crews. A close look at the lion's mouth shows it never really relinquished its hold on the bighorn.

These photos have been making the rounds on the Internet. The Traveler would be interested in learning who took them and hearing their story.