 A detachment of Hunter's force traveled along the Butterfield Overland Mail route and destroyed caches of hay to prevent their use by Union forces; it traveled to within eighty miles of Fort Yuma.In April 1862, a small party of Confederates moving northwest from Tucson met a Union cavalry patrol near Stanwix Station.The skirmish that followed, in which one Union cavalryman was wounded, is often considered the westernmost engagement of the Civil War.