Mark,
Note: Oklahoma was at that time call the Indian Territory, which in turn the CSA considered it part of Arkansas

Nail's Crossing .......1.6 miles, where the Texas Road crossed the Blue River, on the south bank of the Blue is the Site of Fort McCulloch, established in 1862 by General Albert Pike and named for Brigadier General McCulloch, who commanded the Confederate forces in Indian Territory the first year of the Civil War. Fort McCulloch is on private property southwest of Kenefic, Oklahoma.

Mike