Fort Butcher (collected information on this fort)

I have Fort Butcher on a map somewhere in the Great Alluvial Sand Wastes inbetween Kled and the Citadel (Borys’ old haunt).
It would seem it’s added from material in 4E but I can’t for the life of me seem to find the sourcing of the place. Who can help?

I have it located where the map is currently marked “Jura Dai Encampment”. For reference each hex is 6 miles, so about 40ish miles northeast of Tyr. I used the same rough location as the awesome Dark Sun actual play “To Tame a Land”: Dark Sun Ep.01: AD&D 2E | To Tame A Land 01 - A Little Knowledge Part 1 | Lawful Stupid RPG - YouTube