On June 16, 1863, a moving skirmish swept across the prairie near present-day Camp Gruber to the Arkansas River. It was the final action in an unsuccessful attempt by Confederate Colonel Stand Watie and his Cherokee regiment to disrupt Union supply lines to Fort Gibson. Union infantry and cavalry under Colonel Stephen H. Wattles quickly caught up with Watie's forces and defeated them. Watie then retreated with his soldiers and forded the Arkansas River. An estimated 4-10 soldiers on each side were killed.