Thanks to Bryce Suderow for sharing this on the Arkansas message board. I copied the short piece that relates to their trek through the Indian Territory bound for Texas after Price's Missouri Raid.

Excerpts of Letter written by William E. Whitsett, Langhorne’s Company, 12th Missouri Cavalry Regiment, C.S.A. . Found at http://gen.1starnet.com/civilwar/whitsett.htm. Written to his brother Sept. 5, 1900.

From here we horsed on our way, quietly with nothing to eat and crossed the Ark River some eight miles west of here [Sallisaw, Ok.] at what is known as the Big Drift and from here we went out through Limestone Gap crossing Sweet Bugg(?) at Davis on the Widow Flax's which is now known at Atoka, from there out by Armstrong Academy at which place Bob Marley, Sam Cobb, W. T. Hickman, Bud Vaughn, Mart and John Cristen and myself staid all night forcing our stay on Mrs. Lorain Folsum, who was then in charge of the Academy, we crossed Red River the mouth of Island Bayou, near the widow Popes, out by Hoppers and on to Bonham, where I obtained a thirty days Furlough

Wm. E. Whitsett, Sallisaw I.T. Sept 5th 1900

Price's army entered the Cherokee Nation in the vicinity of Cane Hill AR. They moved southwest and crossed the Arkansas into the Choctaw Nation at Pheasant Ford/Pheasant Bluff near present Tamaha OK [Tamaha is Choctaw for "town"] and the location where Watie had captured the steamer J.R.Williams in June 1864. The pursuing Union troops followed just across the Arkansas and then fell back to the north side and camped before marching to Kansas via Ft Gibson. I presume Whitsett moved with Shelby to North Fork Town in the Creek Nation [just north of present Eufaula now under Lake Eufaula] and then back across the Canadian into the Choctaw Nation again and down the Texas Road via Perryville [near McAlester] and Limestone Gap to Mrs. Flacks' place. Limestone Gap is near Stringtown OK. I'm not sure what "Sweet Bugg" means but they crossed Middle Boggy (aka Muddy Boggy) at Davis' Ford to Mrs. Flacks' place where is now Atoka OK. They marched to Armstrong Academy, north of present Bokchito OK at Chahta Tamaha, "Choctaw Town", which was, at the time, the capital of the Choctaw Nation and the frequent meeting place of the 'Indian Nations allied with the Confederacy'. It is unclear whether they marched southwest from Mrs. Flacks' to Boggy Depot and then southeast to Armstrong Academy but this seems likely due to their desperate need for food for men and horses. From Armstrong Academy they went nearly due south to the mouth of Island Bayou where they crossed the Red River into Texas.

Ken