River Dreamer

Most of Guy Thornton's family is thriving on their ranch in southern Arizona, but Samson the mule has grown old and his caretaker, Jasmine, has been struggling with depression since her mother's recent death. Star insists Guy take them to a Mojave Ghost Doctor living on the Colorado River near Parker where Guy's son Trick is starting his career as a large animal vet. The old Mojave man's "cure" involves the family in a mind-bending journey along the Colorado River and a nearly-deadly encounter with his vengeful son and his friends. 

Book Seven of The Arizona Series—novels intertwining Native American mythologies with western / adventure / romances set in the modern American West.