Death where the bad rocks live / C.M. Wendelboe.

Enhanced descriptions from Syndetics:

FBI agent Manny Tanno thought he had left his tribe and the Pine Ridge Reservation behind him years ago. But now with a cold case unearthed in the hot plains sun, he knows that the past never really goes away.

In Badlands National Park, there is a desolate area the Lakota refer to as the Stronghold. General Custer called it hell on earth. During World War II, the Army Air Corps used it as a bombing range. At the end of the war, many unexploded ordnances were swallowed up in its sweltering sands. But that's not all that's buried there...

Sixty-five years after the war, the Sioux tribe has contracted an ordnance removal company to defuse any remaining ammunition in the Stronghold. When the company finds a human arm near a live bomb, Tanno and the Tribal police are called to investigate. As the body is exhumed, two more are discovered. The remains are close together, but the murders were decades apart--and the story behind them is about to blow up...