Devil’s Fork by Jesse Jacobson

Former Navy SEAL Roger Jolly is thrust into a life or death situation during a six-day camping and rafting excursion.
Jolly, now an outdoor adventure guide, sets out in a trip with eleven passengers and his former SEAL brother. He meets a beautiful woman, Jeannie Jenkins, and a budding romance begins. On day two of the trip, an unknown assailant wounds two of the passengers, sinks their boats and cuts off their communication to the outside world, trapping them on a river bank miles from civilization. With his back against the wall, Jolly and Jeannie make a break for it, drawing the shooter’s attention away from the rest of the group. They raft down Devil’s Fork, a forbidden section of the river with ominous, unpassable rapids.
Jolly must solve the mystery of the shooter, protect Jeannie and navigate the dangerous rapids, all with a skilled sniper in hot pursuit.