The McKenzie Sisters Mystery Series

Two sisters . . .

Rose and Cassandra are no ordinary sisters. One is scientifically inclined, lives in Denver, and rides a bicycle like her life—or a case—depends on it. The other rides trains, wields a blade, and keeps her identity as a Pinkerton "under wraps." The sisters also have a knack for solving cases . . . and getting into trouble while doing it. 

Each book takes place in a different Colorado location but they happen simultaneously. They are stand-alone novels and can be read in any order. The McKenzie Sisters Mystery Series was created by Samantha St. Claire.