ARCHEOLOGICAL investigations in the State have not yet reached a point where it is possible to trace the development of Wyoming's prehistoric cultures or to determine their relation to those of the adjacent areas. Certain rock quarries, boulder lodge circles, rock carvings and paintings, and numerous places containing evidence of former human habitation have been surveyed, but the material has not yet been dated or related in a historical sequence.
Aboriginal quarries at the Spanish Diggings, one of the more important sites, cover an area of 10 x 4o miles extending from the southwest corner of Niobrara County into the northeast corner of Platte County. Some of the larger quarries are reasonably accessible and can be reached by following US 20 westward out of Lusk. At a point 22 miles west, a large sign pointing south directs travelers to the diggings at a distance of 11 miles. Here the quarries and shop sites begin, many of them named for scientists who have made repeated explorations in the region (see Tour 6).
Expeditions to explore the sites have been conducted by Harlan Ingers Smith of the Canadian Geological Expedition; Dr. George A. Dorsey ( 1868- 1931), late curator of anthropology of the Field Museum; Dr. Erwin Barbour, of the University of Nebraska; Professor Richard Lull, of Yale University; C. H. Robinson, representing Illinois State Museum; William Henry Holmes ( 1846- 1933), author of Handbook of Aboriginal Americas Antiquities, for the Smithsonian Institution; and Dr. Etienne B. Renaud, of the University of Denver. The Smithsonian Institution sent out a party of scientists in 1915, and since then many of the larger colleges have done likewise. Reports of these various investigations disclose, among other things, that material quarried for implements was obtained from a peculiar stratum of quartzite lying in sandstone, probably selected because its conchoidal fracture left sharp edges. It is noted, also, that rock mining was done entirely with rock tools, such as wedges and hammers. In some instances wedges were