Why is Wyoming's nickname the cowboy state?

A cowboy on a bucking horse was adopted officially as a symbol of the state, which led to some calling Wyoming The Cowboy State.  Wyoming license plates have included the image of a bucking horse and rider since 1936.
A cowboy on a bucking horse was adopted officially as a symbol of the state, which led to some calling Wyoming The Cowboy State.  Wyoming license plates have included the image of a bucking horse and rider since 1936.