The two rails would eventually connect on an historic day in May, 1869 in Promontory, Utah. The Central Pacific, plagued by labor and financial problems, laid down only 50 miles of track in the first two years. To compound their problems, the construction path now faced treacherous terrain that rose 7,000 feet into the high Sierras.

In his painting, The Powder Monkeys, artist Mian Situ honors the Chinese laborers who, in 1865, were hired for $28 per month to do the very dangerous work of blasting tunnels and laying tracks. The Chinese, using techniques they learned at home, were lowered in baskets by rope from the top of cliffs.They hand drilled holes into the granite and packed them with black powder (and later nitroglycerine) to blast tunnels.Many workers risked their lives and perished in the harsh winters and dangerous conditions.