Tombstone grew as a mining town after Ed Schieffelin found silver and gold in the hills in 1877, drawing prospectors, laborers, miners, lawmen, "shady ladies," gamblers, and others hoping to profit from new wealth. Thirty nine million dollars in ore were extracted from the mines from the 1880’s until the 1930’s, aided at first by rich silver and gold ore lying close to the surface and mined largely through hard manual labor with shovels. A lack of plentiful water supply led to mills being built on the San Pedro River, 10 miles from Tombstone, and ore being hauled there by wagons pulled by 20 team horses or mules over steep and rugged terrain. Water then became a deeper problem when it was struck in the Sulphuret Mine at 520 feet and soon encountered in the other mines as well. In 1883, gigantic Cornish style pumps were installed at the Contention and Grand Central Mines, but when the Grand Central pumps burned in 1886, the remaining pumps at the Contention proved inadequate and mining below the water table was suspended. Mining stayed at a low ebb from 1886-1901 until the Consolidated Mining Company formed in 1901, sank a four compartment shaft, built mills, and reconditioned the Contention, Empire, Lucky Cuss, Silver Thread, Toughnut, West Side, and Grand Central. By 1906, the Boom shaft had reached the 1000 ft. level and water was being pumped at 3000 gallons per minute, about 3,700,000 gallons each day. In 1909, defective boiler fuel caused the pumps on the 1000 ft. level to seize and stop, sinking pumps failed, overtaxed boilers ruptured, and all pumping ceased. Although new compressors and boilers solved that immediate crisis, the cost of fighting the water, falling silver prices, and insufficient high quality ore made mining economically unfeasible, and in 1911 pumping stopped and the 600, 700, 800, and 1000 foot levels of the Boom shaft were allowed to flood. Mining continued for some years afterward, but it never again matched the production of Tombstone’s early years.