sentences:  The Comstock was the first important silver-mining district in the United States, and its discovery stimulated a great deal of prospecting for silver across the Great Basin area of the United States.The resulting silver rush led to many other silver discoveries in Nevada, including El Dorado Canyon (1861), Austin (1862), Eureka (1864), and Pioche (1869).The Rochester Mine is the only operating primary silver producer in Nevada and the second largest in the USA (after the Greens Creek mine in Alaska).