12-year-old Kate Alexander as she and her family travel west in 1843. When Kate's father decides to sell their Ohio farm and move to Oregon, the family has many regrets. Nonetheless, they pull up stakes and begin the long journey across the plains. The bumpy roads, slow pace and cramped living conditions prove dreary, and everyone misses the comforts of home. When the Alexanders join a wagon train in Missouri, they become acquainted with the high-spirited Thompsons from Kentucky. Kate becomes friends with Tildy, the only daughter; together, the girls explore the prairie, meet an Indian, survive a twister and save a boy's life. Most of the novel focuses on the day-to-day hardships of pioneer life and the attitudes of the people. The monotony of the journey and constant threat of adversity create tensions between the travelers, yet even the worst enemies join forces in times of need.