In 1843, Kate Winfield is among the first of what will be eventually 300,000 Americans who will travel thousands of miles up the Oregon Trail in search of a better life. Through perilous river crossings, blistering heat, choking dust clouds, freezing nights, and the tragic passing of her mother, Kate grows up emotionally and spiritually and begins to dream of becoming a medical missionary to the Inidians. But that dream is challenged when a plauge threatens to wipe out the entire wagon train.