The Cowskin Prairie battle of 6 June 1862 is found in the Official Records as the Skirmish at Grand River, I. T. Colonel Charles Doubleday (2nd Ohio Cavalry) commanded the detachment that had marched south from Fort Scott. His 1000 strong force comprised the 2nd Ohio Cavalry, the 9th Wisconsin Infantry, and the 2nd Indiana Battery (aka Rabb's Battery).
Doubleday's report (OR, Vol. 13, p. 102) reads in part as follows:
"I arrived at Grand River on the same day [6th June] about sundown, and learned that the enemy were encamped 3 miles distant to the number of 1,500, commanded by Stand Watie, Coffee, and others. I ordered the First Battalion, Second Ohio Cavalry, across the river, to take position south of the rebel encampment, advancing at the same time with my artillery, supported by infantry, in skirmish order, through the woods to the crossing, which was effected by the entire force by 9 p.m., the enemy's pickets merely firing a few scattered shots as they fell back. Not having daylight I could not accurately ascertain their precise positions, except in the camp of Stand Watie, which was in a grove. I ordered the artillery to the front, and from a distance of about 500 yards threw a few shot and shell into their camp, causing considerable commotion, audible to us."
"About 1 a.m. I ordered my troops to lay on their arms, having previously thrown out a strong chain of cavalry pickets; but during the night the enemy escaped along the brush-wood and made a rapid march toward Fort Smith."
Colonel Stand Watie (2nd Cherokee Mounted Rifles) filed a report on 1 June 1862 (OR, Vol. 13, pp. 94-95) that stated that on 31 May 1862 Coffee's Missouri Cavalry Regiment was "something more than 200 strong".