Tiger Swallowtail at Prince William Forest Park (courtesy of Kirsten Talken-Spaulding/NPS)

U S S Arizona Memorial at Pearl Harbor (courtesy of Christy Splechter/NPS)

U S S Arizona Memorial at Pearl Harbor (courtesy of Christy Splechter/NPS)

Arches National Park Ranger Murray leads the Fiery Furnace Hike (courtesy of Dan Ng/NPS)

Hiker's reflection in pool at Arches National park (courtesy of Sara Bartels)

Bryce Canyon National Park Visitors gaze at the constellations and Milky Way (courtesy of Dan Ng/NPS)

Casa Grande National Monument American Indian Music Fest 2009 (courtesy of John Dodson/NPS)

Surfing at Buffalo National River's Clabber Creek shoals (courtesy of Mark Robinson/NPS)

Ranger conducts Balcony House tour at Mesa Verde National Park (courtesy of Dan Ng/NPS)