ABSTRACT
The period of geomorphic investigation about to be discussed brought with it a freshness of approach and opinion largely because it involved the exploitation of a novel environment. Some of its discoveries provided no more than confirmation of theories evolved in Europe, but it would be misleading to allow the assessment to end there. The explorers of this new environment, for they were explorers, viewed the evidence of nature with minds that were largely free from foreign preconceptions. What they saw around them was a world different from anything that they had ever seen or imagined. Even if foreign ideas had been applicable, the geologic evidence of the western United States provided an explanation of its own evolution that was at once so simple and clear that no other interpretation was needed. All who visited the area were impelled to the same conclusion. Historical events largely decided the moment when this striking geological evidence would be discovered. The period 1790 to 1890 was the great era of westward expansion in the United States but this unique and fascinating story lies outside our main theme. We are concerned only with the first scientific investigators of these wild, inland territories. Yet thereby we plunge at once into the epic of the West and, as perhaps might have been expected, meet straightaway a new breed of geologists; not the studious, often-theorizing specimens roaming the hills of western Europe but strong, independent men filled with a fire and spirit acquired in the hardy trials of an expanding pioneer society.
