Jean,
Oops! I somehow wiped out my response.
The skirmish to which you refer took place on May 18 a little ways west of Butler, Bates County, when Thurman's guerrillas attacked a Union detail of forage gatherers at Miami Ford of Miami Creek. The Union loss to the First Iowa Cavalry was three killed and the sergeant wounded at no guerrilla loss. It was not a massacre in the military sense as both sides were armed, even though the outcome was one-sided. Sources include the pamphlet "Civil War Years in Bates County," printed in Butler about the 1960s; the 1883 Bates County history, and the 1897 Bates County history.
Did you have a particular question about this skirmish?
Bruce Nichols