For those of you who keep track of the national parks with stamp collections, get ready to add two new stamps to your albums.

If you were lucky enough to be in Bryce Canyon National Park on Tuesday, you would have been surrounded by one of the prettiest days of the year, as these photos clearly show.

There are national parks that focus on geology, that provide windows into ancient civilizations, and which honor westward expansion. So should one that preserves fossilized mammoth bones be added to the mix?

Military personnel, federal employees and elected officials take an oath of allegiance or oath of office, but during the American Revolution there was a lot at stake for those who promised "true allegiance to the United States of America"—in writing. One of those historic documents was recently donated to Valley Forge National Historical Park.