Other parks have private landing strips, but Grand Teton National Park in Wyoming is the only U.S. national park that contains a commercial airport. Opened in the 1930s, Jackson Hole Airport became part of the park in 1943, when President Franklin Delano Roosevelt recommended expanding Grand Teton National Park to include Jackson Hole National Monument. That proposal was finalized in 1950. Rather than turn the area into a ghost town, as some local businessmen feared, it brought robust tourist trade to the region. Today, Jackson Hole Airport is the busiest airport in Wyoming.

Which natural formation played a key role in the 1977 film "Close Encounters of the Third Kind"?

A) Devils Tower in Wyoming

B) El Capitan in California

C) Landscape Arch in Utah

D) Zuma Rock in Nigeria

Previous answer: Bosnia and Herzegovina, Kosovo, San Marino and Spain are the only four countries whose national anthems don't have official lyrics.

TRIVIA FANS: Leslie Elman is the author of "Weird But True: 200 Astounding, Outrageous and Totally Off the Wall Facts." Contact her at [email protected].