The only systematic exploration of the was made by the under my charge, in the summers of 1869 and 1871. In the same years Powell made of the , and in so doing traversed the eastern end of the range in his boat journeys down the meandering canyons of the . In the summer of 1871 Hayden made a hasty reconnaissance along the northern slopes of the range, penetrating the central core at a single point near the head of Blacks fork, where he found fossils in the flanking limestones and “suspected” that the underlying s might be from their resemblance to the . During the seasons of 1874 and 1875 Powell headed parties that studied the geology of the eastern part of the range and the surrounding and regions. From that time until 1903 there is no record of any geological study of the range. At the time when the field work was being carried on, what was known of the geology of the n region was mainly derived from observations of geologists accompanying military expeditions, generally as surgeons.
— SAMUEL FRANKLIN EMMONS