In the first full-length biography of Luther Sage "Yellowstone" Kelly (1849-1928), Jerry Keenan provides a comprehensive look at this extraordinary man of the American West. After joining the army at the close of the Civil War and spending three years at outposts in Minnesota and Dakota, Kelly headed west to begin life as a frontiersman, explorer, and army scout and came to know the Upper Missouri and Yellowstone River valleys. In midlife, he explored Alaska, fought in the Philippines, and served as agent at the San Carlos Apache reservation in Arizona. Later, he prospected in Nevada before finally retiring to the quiet life of a California orchardist.

Based on Kelly's memoirs and personal correspondence, this book offers insight into many of the prominent figures he knew, including George Bird Grinnell, Col. Nelson A. Miles, William F. "Buffalo Bill" Cody, and President Theodore Roosevelt.