The Pathfinder by James Fenimore Cooper( Leatherstocking Tale#3)

In the third installment of the Leatherstocking Tales, Cooper takes his main character, here called the Pathfinder (Natty Bumppo) and examines his role as an explorer for British/Colonial forces in the forests and islands around the Great Lakes. The story is a classic historical adventure/romance and Bumppo falls in love, for the first and only time in the five novels, only to see his choice fall in love with another man - a younger man and good friend of Natty's. Probably the best of the five Leatherstocking novels."