Reparto (por orden de créditos)
Guy Adema
Physical Scientist
Janet Babb
Ranger at Hawaii Volcanoes National Park
Sonny Bass
Wildlife Biologist
Phil Brease
Geologist
Kelly Bringhurst
Professor of Geology at Dixie State College
Sharon Brussell
Ranger at Canyonlands National Park
Mike Buchheit
Director at the Grand Canyon Field Institute
Charlie Callagan
Ranger at Death Valley National Park
Colby Coombs
Alaska Mountaineering School
Chris Day
Guide at Emerald Air Service
Scott Gediman
Assistant Superintendent at Yosemite National Park
David Michael Gee
Narrator
Lyman Hafen
Executive Director at the Zion Natural History Association
Troy Hamon
Acting Superintendent at Katmai National Par
Jake Lowenstern
Volcanologist
Jim Mead
Geologist at Northern Arizona University
Michael Ross
Instructor at Yosemite Association
Alan Van Valkenburg