Tombstone is a historic city in Cochise County, Arizona, United States, founded in 1879, by Ed Schieffelin in what was then Pima County, Arizona Territory. It was one of the last wide-open frontier boomtowns in the American Old West. The town prospered from about 1877 to 1890, during which time the town's mines produced US$40 to $85 million in silver bullion, the largest productive silver district in Arizona. Its population grew from 100 to around 14,000 in less than seven years.