Eva,

I hope Bryan Howerton, the "real" Arkansas personnel expert responds to this posting. From his work on the Ed Gerdes' Original Arkansas Civil War Home Page I find a:

ROUARK, C.C. - PVT - 10 Mar 1863 - Bellefont, AR in HARRELL'S BATTALION ARKANSAS CAVALRY CSA, COMPANY D
http://www.couchgenweb.com/civilwar/harreld.htm

Also known as 17th Bn Ark, Cav Microfilm Roll #35 Ark (The officers and men of this unit enlisted in Aug 1862 in the infantry under Col. C.W. Adams which was disbanded and the men transferred to the command of Gen. Cabell, of which this is a part.)

The only candidate I can find for John Roark is a:

ROARK, J. P. - PVT in 1ST BATTALION (STIRMAN'S) ARKANSAS CAVALRY CSA
http://www.couchgenweb.com/civilwar/stirmand.htm

Jim Martin