File:The national parks portfolio (1917) (14596084129).jpg

Identifier: nationalparkspor1917yard (find matches)
Title: The national parks portfolio
Year: 1917 (1910s)
Authors: Yard, Robert Sterling, 1861-1945 United States. National Park Service
Subjects: National parks and reserves
Publisher: Washington, D.C. : U.S. G.P.O.
Contributing Library: Harold B. Lee Library
Digitizing Sponsor: Brigham Young University

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bottoms to the mountains tops is the story. According to one fa-mous theory of creation,theearth has been contractingthrough unnumbered cyclesof time. Just as the squeezedorange bulges in places, sothis region was forced up-ward. Then it cracked andthe western edge was thrustfar over the eastern edge.The edge thus thrustover was many thousandsof feet thick and disclosedall the geological stratawhich had been depositedat that time. In the manycenturies of centuries sincethat time all these strataexcept the next to the oldestin the earths history havebeen washed away, disclos-ing here rocks which geolo-gists think are at least eightymillions of years old. Under this incalculablepressure from its sides andbelow, the bottom of thesea gradually rose and be-came dry land. The pressurecontinued, and the earthscrust, like the skin of thesqueezed orange, bulged inlong irregular lines. In timethese l^ecame mountains. Photograph by Ellis Prentice Cole Iceberg Lake Where Floes Drift in August 80
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^--is^ kffea^siasiJg Photograph by L. D. Lindsley One of the Wildest Spots on Earth Is Ptarmigan Lake Then, when the rocky crust could no longer stand the strain, it cracked. Gradually the western edge of this great crack was forced upward and overthe eastern edge. This reheved the internal pressure and the overlappingedge settled into its present position. Geologists call this process faulting. The edge thus thrust over was many thousand feet thick. It disclosed allthe geological strata of the earth which had been deposited up to that time.In the many centuries of centuries since, all these strata have been washedaway, except the very oldest, those of the Algonkian period, which geologiststhink are at least eighty millions of years old. It is this ancient rock whichgives the Glacier National Park its individuality. Then this remaining edge of rock crumbled into peaks and precipices. Upon these the rains of uncounted centuries of centuries since have fallen,and the ice and the frost a

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