On May 10, 1869, the Central Pacific and Union Pacific railroads met at Promontory Summit, Utah, joining 1,776 miles of track. The Union Pacific built westward from Omaha, Nebraska, while the Central Pacific laid track eastward from Sacramento, California, through the Sierra Nevada. Over 13,000 Chinese laborers comprised 80-90% of the Central Pacific workforce, drilling tunnels through granite under hazardous conditions. CPRR President Leland Stanford tapped a ceremonial golden spike to mark the connection. The rail link reduced cross-country travel from months by wagon to roughly one week.