Buffalo jump blues

"In the wake of Fourth of July fireworks in Montana's Madison Valley, Hyalite County sheriff Martha Ettinger and Deputy Sheriff Harold Little Feather investigate a horrific scene at the Palisades cliffs, where a herd of bison have fallen to their deaths. Victims of blind panic caused by the pyrotechnics, or a ritualistic hunting practice dating back thousands of years? The person who would know is beyond asking, an Indian man found dead among the bison, his leg pierced by an arrow. Farther up the valley, fly fisherman, painter, and sometime private detective Sean Stranahan has been hired by the beautiful Ida Evening Star, a Chippewa Cree woman who moonlights as a mermaid at the Trout Tails Bar & Grill, to find her old flame, John Running Boy. The cases seem unrelated-- until Seans search leads him right to the brink of the buffalo jump" -- Amazon.com