The Battle of Round Mountain, The name originates from a single writer who noticed a curl at the end of Mountain on the report and changed 'mountain' to its plural. This distinction supports the Yale site as to where the battle was fought because that location has two twin mounds. November 19, 1861. The location mentioned has never been shown as being the actual location of the engagement, and is disputed by many historians.

Col. Douglas H. Cooper, Confederate commander of the Indian Department, was unable to reconcile differences with Chief Opothleyahola, commander of a band of Unionist Creeks and Seminoles. Cooper set out on November 15, 1861, with about 1,400 men to either compel Opothleyahola 's submission or “drive him and his party from the country.” Cooper's force rode up the Deep Fork of the Canadian River to find Chief Opothleyahola’s camp deserted. On November 19, Cooper learned from captured prisoners that part of Opothleyahola’s band was erecting a fort at the Red Fork of the Arkansas River.

Cooper’s men arrived there around 4:00 p.m. Charging cavalry discovered that Opothleyahola’s followers had recently abandoned their camp. The Confederates located and followed stragglers; the 4th Texas blundered into Opothleyahola’s warriors on the tree line at the foot of the Round Mountains. The Federal response chased the Confederate cavalry back to Cooper’s main force. Darkness prevented Cooper's counterattack until the main enemy force was within 60 yards. After a short fight, Opothleyahola’s men set fire to the prairie grass and retreated.

The following morning, Cooper advanced on Opothleyahola’s new camp but found that the Federal forces had fled. The Confederates claimed victory because Chief Opothleyahola had left the area.

This was the first of three encounters between Opothleyahola’s Union bands and Confederate troops. The chief was forced to flee to Kansas at the end of the year.

The Confederate loss in the engagement was 1 captain and 5 men killed, 3 severely and 1 slightly wounded, and 1 missing. Opothleyahola lost about 110 killed and wounded.

Battle of Round Mountain
Part of American Civil War
Date November 19th, 1861
Location Location disputed, near Keystone, or Yale, Oklahoma
Result Confederate victory
Loyal Indians Confederate States of AmericaConfederate States of America
Commanders and leaders
Opothleyahola Douglas H. Cooper
Unknown 1,400 men
Casualties and losses
110 casualties 6 fatalities
4 wounded
1 missing