Cruzatte & Maria : a Gabriel Du Pré mystery / Peter Bowen.

Enhanced descriptions from Syndetics:

In his eighth outing, Metis-Indian fiddler, tracker, and amateur sleuth Gabriel Du Pre is called upon by his daughter Maria and her fiance to act as historical advisor for a documentary film about the Lewis & Clark expedition. Du Pre is the descendant of Pierre Cruzatte, one of the scouts who accompanied Lewis and Clark during their expedition, and has the relevant know-how to authentically recreate props. When Du Pre arrives at the shooting site, located in a remote region of Montana along the Missouri River, he finds himself in a volatile situation: major trouble is brewing between the local community and the tourists and the film makers of the documentary who are descending upon the historical site with increased frequency. The hostility takes its toll on the film production: the star quits and someone has set fire to the props. Then two bodies, that of a photojournalist and his companion who were retracing Lewis & Clark's route, are fished out of the Missouri -- shot to death. A disgruntled local? Or someone with even more insidious intentions? Meanwhile, Du Pre stumbles upon a secret cache left behind by the original Lewis & Clark expedition, containing Merriweather Clarks' journals. Suddenly, the backwater locale is swarming with media, and tensions rise to a boiling point. Peter Bowen combines a thorough knowledge of our national history with local atmosphere and a slew of offbeat characters to create an infatuating read.