Greetings from the visitor center at Scotts Bluff National Monument in western Nebraska. It is Wednesday afternoon and outside it is hot and windy. The monument is a few miles outside the town of Scottsbluff, where we spent last night in the municipal campground.

Yellowstone National Park rangers on Wednesday put down a female black bear that had come to rely on humans for food.

Here is the list of all 392 NPS units. How many have you visited? Start counting, and let us know.

Lake Texoma is a hugely popular flatwater playground on the Texas-Oklahoma border. It was once, albeit briefly, a national park.