Season 5

Cullen Bohannon finds himself a stranger in a strange land: Truckee, California. Home to the headquarters of the Central Pacific railroad, this rough mountain railroad town teems with thousands of Chinese workers who are foreign in language, culture and traditions. While grappling with the challenges of corralling his new workforce, Cullen leads the Central Pacific’s herculean effort to tunnel through the Sierra Nevada mountains, sometimes achieving only inches a day in the race to complete America’s first Transcontinental Railroad.