Bill, Lieutenant-Colonel Geoghegan was at Camp Hope, near Austin, Arkansas, when the battle was fought, so command of the regiment devolved upon Maj. Samuel Slade Bell, of Ashley County. Major Bell was slightly wounded in the hand during the engagement. He was promoted to colonel on December 22, 1862, succeding Colonel Pleasants. I recall reading a biographical sketch of Col. Samuel S. Bell which confirmed the above, and I may have a copy of it around here somewhere. I'll see if I can find it.
The regiment was designated as the 29th Arkansas Infantry from its initial organization until after the battle, when it was redesignated as the 37th Arkansas Infantry.