In 1869, Prussian-born mining engineer, Adolph Sutro, began work on four-mile-long tunnel through the solid rock of the Comstock Lode. Miners sank shafts deeper and deeper into the rock in search of more silver and gold. The further into the Earth they mined, the more water they encountered. This had to be pumped to the surface at great expense.
Enter Adolph Sutro. With his nifty invention of horizontal drainage, mine water would drain through a tunnel, minus expensive pumps. Handily, these tunnels could also be used to move men and ore in and out, greatly reducing transportation costs.
Everyone agreed the tunnel would be a boon to the Comstock. But they worried that Sutro would use his tunnel to take control of the entire Lode, and progress was continually slowed because of that fear. It was only by securing European capital that Sutro able to complete the $5 million project in 1878.
Every bit as successful as promised, Sutro’s tunnel drained two million gallons of water per year, and greatly reduced transportation costs. Alas, by 1878, the richer sections of the Comstock Lode had been tapped out, and profitability declined. Sutro, however, sold his tunnel in 1879 at a extraordinary profit, and moved to San Francisco where he became one of the city's largest landowners and mayor from 1894 to 1896.