Apparently Dr. Hayden* and Professor N. H. Winchell† were the earliest geologists to visit the Black Hills of Dakota; the former while engaged in his extended surveys in the Northwest, the latter as the geologist of General Custer’s expedition, of 1874. The works of both in this region were no more than reconnaissances, and the pre-Cambrian rocks received comparatively little attention.
One of the consequences of these preliminary trips and exaggerated reports as to the richness of the hills in gold was a systematic survey of the area by the Rocky Mountain division of the United States Geological Survey under the direction of Major Powell. This work was entrusted to Messrs. Henry Newton and Walter P. Jenney—Newton as geologist and Jenney as mining expert. Newton’s death occurred before his report was ready for the printer, and it was edited by Mr. G. K. Gilbert. The large . . .