As the sun set over the Sonoran Desert, the animals came out to play. The deer grazing among the saguaro were probably mule but could have been white-tailed — it was tough to say at dusk with only mini red-light flashlights in hand instead of binoculars. The bird that perched on a tree branch for a few seconds before flying away had the distinctive silhouette of an owl. There was no mistaking the yips and howls of coyotes.

Does Yellowstone National Park witness a "normal" number of earthquakes each year?

Work to repair a moat wall at Dry Tortugas National Park in Florida will spur a 45-day closure of the Garden Key Campground later this spring.

Now's your chance — possibly that once in a lifetime chance — to paddle your kayak in Death Valley National Park.