Geological Survey Bulletin 104 The Glaciation of the Yellowstone Valley North of the Park

The local glaciers of Quaternary times, of which evidences abound throughout the highest portions of the Rocky mountain cordillera, attained an unusually extensive development in that broad elevated region known as the Yellowstone Park. It was indeed the center of a considerable ice sheet whose glaciers spread out and down the valleys leading from this mountain region in all directions.¹ In the northern part of the park two streams of ice found an outlet for their united flow northward down the valley of the Yellowstone, and they have left impressive memorials of the power and size of this stream that at once attract the attention of the observant traveler on the way to the famous geyser basins of the park. The number and size of the erratic bowlders scattered so abundantly over the valley floor and perched high up on the mountain slopes, can not fail to impress the beholder, while the second canyon of the Yellowstone, known as Yankee Jim canyon, through which the river has cut its way to the broad mountain encircled lower valley, is a grand and perfect piece of ice sculpture that affords striking proof of the power and magnitude of the glacier which once filled the valley.

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¹See Geol. Hist. of Yellowstone National Park, by Arnold Hague: Trans. Am. Inst. Min. Engrs. 1888.

While studying and mapping the geology of a portion of the country north of the Yellowstone Park, under the direction of Mr. Arnold Hague, and for the United States Geological Survey, I found a long desired opportunity to study the glaciation of this interesting region.