From 1908 until 1954, Donald Baxter MacMillan spent nearly 50 years exploring the Arctic—longer than anyone else. Growing up near the ocean, and orphaned by 12, MacMillan forged an adventurous life. Mary Morton Cowan focuses on the vital role MacMillan played in Robert Peary's 1908-09 North Pole Expedition, as well as his relationships with explorers Peary, Matthew Henson, and Richard Byrd. She follows his long and distinguished career, including daring adventures, contributions to environmental science and to the cultural understanding of eastern Arctic natives. Working closely with the Peary-MacMillan Arctic Museum at Bowdoin College, Cowan showcases many MacMillan documents and archival photographs, many MacMillan's own in this winner of the John Burroughs Nature Books for Young Readers Award.