Statement of Significance (as of designation - June 23, 1986):
A vestige of an early 20th-century copper mining camp, Kennecott represents the mining techniques of the era. The mines here were among the nation's largest and contained the last of the great high-grade copper ore deposits of the American West. The world's first ammonia-leaching plant for extracting concentrations of ore from low-grade ores was designed and first successfully used on a commercial scale here. The camp is little changed since its 1938 closing.