In Season 5, Cullen Bohannon finds himself a stranger in a strange land – the mountain town of Truckee, California, home to the Central Pacific Railroad. This rough railroad town teems with thousands of Chinese workers, foreign in language, culture and traditions. Despite the challenges of corralling his new workforce, Cullen leads the herculean effort to tunnel through the Sierra Nevada Mountains, sometimes achieving only inches a day in the race to complete the first Transcontinental Railroad.