John Charles Fremont is a controversial pioneer who, initially as an army officer, fights against the short-sighted authorities during the Mexican-American war. In 1842, Fremont embarks on his greatest adventure yet when he takes the lead in an expedition to map the road to Oregon; a 2,400-mile (3,400-mile) route that runs from Missouri to the mouth of the Columbia River. It is the first step towards the conquest of the entire North American continent. In his mission, Fremont encounters hostile Indians, the Mexican army and, last but not least, his own patrons. He comes into contact with many historical figures, such as Kit Carson, Jim Bridge, John Sutter and President Abraham Lincoln. Alice Krige plays Jessie Benton, the determined daughter of a senator and the wife of Fremont.