“Peter Bowen does for Montana what Tony Hillerman does for New Mexico” (Midwest Book Review).
 
Gabriel Du Pré’s aunt Pauline has burned through more than her share of husbands, so it’s no surprise when she shows up in Toussaint complaining that the latest one, Badger, has run off. Du Pré, the Métis Indian fiddler, retired cattle inspector, and sometime deputy, agrees to go looking for her man. He finds him shot, execution-style, in the wilds of the Montana countryside. A chat with his contacts at the FBI reveals that Badger, a small-time drug smuggler, had been working for them since his last arrest. Pauline’s husband was bait, but the big fish got away.
 
The last lead was to a cabal of wealthy gamblers who pass their time racing horses in the barren Montana brush. To infiltrate their tight-knit syndicate, Du Pré goes undercover, lining up his own horse and jockey. He must tread lightly, because horses are not the only things these men shoot.
 
Gabriel Du Pré’s foray into the world of illegal horse racing is “as consistently entertaining as its predecessors. [Du Pré], ever skeptical of the modern world and its institutions, places his faith in people, the land, a hand-rolled smoke, and the occasional ditch-water highball” (Booklist).

Stewball is the 12th book in The Montana Mysteries Featuring Gabriel Du Pré series, but you may enjoy reading the series in any order.