a rich deposit of silver & gold discovered in 1859 in W Nev.: virtually depleted by 1890
Origin:
after H. T. Comstock (1820-70), who held first claim to it
See Comstock Lode in American Heritage Dictionary 4
A rich vein of gold and silver discovered in 1859 at Virginia City in western Nevada. Because of wasteful mining techniques, it was largely abandoned by 1898.