Heading west from the City of Rocks on the California Trail, emigrants aimed toward Granite Pass, the gap in a distant ridge six miles away, as their next goal after the eastern routes had merged. Granite Pass was a critical funnel through which emigrants poured from the eastern prairies toward the Humboldt River valley to the west. In the summer of 1850, an estimated 50,000 emigrants, 100,000 animals, and 20,000 wagons passed through this valley, consuming the grass and anything that would burn and sending clouds of fine white dust skyward under feet, wagon wheels, and hooves. Before 1848, someone standing here and looking at Granite Pass would have been standing in Oregon and looking into Mexico.