Castleton Resources LLC operates exploration and production fields. The group is controlled by Castleton Commodities. The company was formed in 2014 and acquired EDF's East Texas assets in 2015 as well as Anadarko's East Texas assets in 2016. In 2019, Castleton acquired Shell's East Texas and North Louisiana assets. The company will be renamed TG Natural Resources after Tokyo Gas takes majority control in August 2020.