The geologic history of the Uinta region has been described by King and Emmons in the reports of the U. S. Geological Exploration of the Fortieth Parallel, and of the eastern portion by Powell in his Geology of the Uinta mountains. For more than 30 years these reports have comprised the extent of our knowledge of this interesting section. Recently Berkey published in the Proceedings of this Society an account of a reconnaissance in the Duchesne region and discussed the bearing of his observations on the stratigraphy and structure. The 40th Parallel geologists had studied the ranges of northern Nevada and Utah, while Powell’s previous work had been in the Grand canyon of the Colorado and the plateau region of eastern Utah. The nomenclature and correlations of the two explorations varied considerably.
Having taken part in several reconnaissance trips in Nevada and northern, central, and western Utah in previous . . .