The Edge Rover chronicles the expansive life of Isaac Slover, a fur trapper who was born in Pennsylvania during the Revolutionary War and who ranged throughout the early American West. The variety and extensiveness of Slover's encounters among Indigenous peoples and the Hispanic Southwest distinguish his experience from that of other "mountain men" of his time. A lifespan from 1777 to 1854 meant that Isaac Slover saw a transformed America, and he endured through frequently shifting borders, particularly in what became the young country's southwest region. Among his numerous adventures are a youth consumed by the Revolutionary War in Western Pennsylvania, then later farming in Kentucky, trapping and trading in New Mexico, and finally making his way to Southern California. Throughout, Slover sifted between cultures, jumped across borders, navigated conflict, and hid along the margins of history. Sparse evidence documents Slover's adventures, but what remains is meticulously compiled here for the first time by Timothy E. Green, who grew up with fireside tales of the mountain man's exploits. At any given stage of his life, Isaac Slover can be situated at a critical juncture in the history of the West, roving beyond the edges and back again. The Edge Rover is therefore a welcome addition to early American West biographies, showing that boundaries, borders, and identities during this early period could be as fluid and wild as the land itself.