Chuck, in October 1864 a large wagon train of supplies was sent from LR to FS. Also Gen. Francis Herron went along with a cavalry escort to ascertain the situation at the fort. One of the soldiers in his escort from the 11th Missouri (Robert Wiles) left a diary of the journey as well as other adventures in Arkansas & the Indian Territory. They arrived ahead of the wagon train on Nov. 7th, 'we arrived to our destination by 1 o'clock. We found the soldiers here almost in starvation and all the cavalry regts are dismounted on account of the horses had been starved to death'. He goes on to mention that the men had been issued 10 days worth of quarter rations.
Also, in the Official Records Thayer wrote to Steele on Dec 17 regarding the impending evacuation of the fort that he had 27 artillery pieces but no artillery or cavalry horses. Also wrote later that he had 150 wagons with no teams that would have to be destroyed.
On January 14th after the order to evacuate had been rescinded Gen. Reynolds wrote to Halleck that Fort Smith was nothing more than a dead weight on the department & that 5,000 animals had died there for want of forage.
The Feb 1st returns for the department lists all of Thayers cavalry, the 2nd 6th & 14th Kansas, & 1st Arkansas as all dismounted.
Indeed, the HQ in Little Rock wanted to abandon the whole frontier district. That would have been Fort Smith, Fayetville, Clarksville, probably some more posts. It was a grim situation in western Arkansas the winter of 1864.