In 1843 Kate Winfield is among the first of what will be eventually be 3000,000 Americans who 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 Indians.  But that dream is challenged when a plague threatens to wipe out the entire wagon train.