The 8,416-acre Longhorn Army Ammunition Plant (LHAAP) installation is located between State Highway 43 and Caddo Lake in Karnack, Harrison County, Texas, approximately 14 miles northeast of Marshall, Texas, and approximately 40 miles northwest of Shreveport, Louisiana. The site is in a rural area and operated from 1942 to 1997, historically manufacturing TNT, rocket motors and various pyrotechnic items.
