Another Man's Moccasins
(book #4 of the Walt Longmire Mystery Series)
by Craig Johnson. OK. I kinda like Walt Longmore and Henry Standing Bear. These are entertaining books and easy to read. This book switches back-and-forth between the investigation into the death of a young Vietnamese girl found in Absaroka County, and Walt's and Henry's time in Vietnam. The stories are interconnected, along with a parallel story of a very large Crow Indian named Virgil White Buffalo. Virgil also has a Vietnam story and Walt helps him to work through it.
Another good story that has big hats and rattlesnakes as well.