Robbers Roost: James Reasoner: Amazon.com: Kindle Store: Originally published as Powell's Army: #4 by Terence Duncan
Three-fingered Jack and his gang of road agents had a craving for money and a place to spend it. After hijacking an rmy payroll wagon and killing the troopers riding guard, they hightailed it into Virginia City, where anything could be had for the asking by a hardcase with a fat poke. But hot on their trail was hard-hitting trio of undercover agents known as Powell's Army. They knew Montana lived by the law of the gun. And that meant bracing Jack's killer gang before the vigilantes did---to make sure they stretched hemp the legal way!
Thundering out of the past. A trio of deadly enforcers ride the range to adventure with one military misfit. Three men and one red-headed woman unchained lightning in a savage, lawless land, the U.S. army's secret weapon, dispensing their own fiery brand of frontier justice throughout the American west, Violent, untamed, and unpredictable--nothing can stop them.