On this day in 1869, the famous Prussian-born mining engineer, Adolph Sutro, begins work on one of the most ambitious western engineering projects of the day: a four-mile-long tunnel through the solid rock of the Comstock Lode mining district.
One of the richest silver deposits in the world, the Comstock Lode had been discovered by prospectors in 1859, and it quickly became the focus of the most intensive mining activity in the West. But as miners sank shafts ever deeper into the rock in search of more silver and gold, they began to encounter large amounts of water that had to be pumped to the surface at great expense. If only some means could be found to drain the water horizontally, the mining companies would save a fortune.
Adolph Sutro's tunnel was intended to do just that. Sutro-who had already demonstrated his technical brilliance by inventing a new way to extract silver from waste rock-proposed to blast a large horizontal tunnel right through the rock of the neighboring Mt. Davidson and straight into the heart of the Comstock mine. Mine water would thus drain through the tunnel without need for expensive pumps, and the mining companies would also be able to use the tunnel to move men and ore in and out of the mine, greatly reducing transportation costs.
While all involved agreed that technically Sutro's tunnel would be a boon to the Comstock, progress on the project was continually slowed down by resistance from some of the major mining interests who feared that Sutro would use his tunnel to take control of the entire lode. Only after securing European capital was Sutro able to complete the $5-million project in 1878.
Every bit as successful as promised, the Sutro tunnel drained some two million gallons of water from the mines per year and greatly reduced transportation costs. Unfortunately, by 1878, the richer sections of the Comstock Lode had been tapped out, and the mine had begun to steadily decline in profitability. Sutro, though, succeeded in selling his tunnel in 1879 at a fantastic profit. He moved to San Francisco where he became one of the city's largest landowners as well as the city's mayor from 1894 to 1896.