Vintage THE MYSTERY AT RUSTLERS' FORT by Troy Nesbit

THE MYSTERY AT RUSTLERS' FORT by Troy Nesbit
Illustrated by Frank Nicholas
WHITMAN PUBLISHING COMPANY RACINE, WISCONSIN

Hardcover Book is in fair condition, sold as a reading Copy. Missing the outside of the binder. Please see all photos.
Phil and Buzz are teenaged cousins who join Buzz's naturalist parents and little sister, Kitsy, on a summer-long research trip to the North Rim of the Grand Canyon. It is the height of the 1950s uranium boom in the Southwest, and the boys sneakily get hold of a Geiger counter to hunt for the element, not realizing that mining is illegal in the national park. Still,the Geiger counter helps to solve a mystery that has plagued the campers all summer long: the constant presence throughout their adventures of a strange character they call "The Dinosaur." Along the way, the boys are introduced to the canyon's natural history, from Kaibab squirrels to mountain lions, bats, and more.