Set in northern Vermont in 1930, On Kingdom Mountain recounts the life and times of Miss Jane Hubbell Kinneson. A renowned local bookwoman and bird carver, she is the sole proprietor and last resident of a remote and wild mountain situated on the U.S.–Canadian border, now threatened by the "Connector," a proposed new highway over her mountain. On Miss Jane's fiftieth birthday, a mysterious stunt pilot and weathermaker enters her life, crashing his biplane onto the frozen lake at the foot of the mountain. He brings with him a riddle—handed down from his grandfather—containing a clue to the whereabouts of $100,000 in stolen gold that may be buried on Miss Jane's property. As she and the footloose aviator befriend each other and begin to search for the treasure, Miss Jane finds herself confronted by the most important decisions of her life.