The plant was spread over a fairly wide area immediately south and west of McGregor, TX, and was begun about 1942-1943. It borders on the city limits, was spread out to decrease the size of an accidental explosion and it was used to load powder/explosive mat'l into shells and bombs made elsewhere, I believe. I'd not say when it actually opened but it made a significant contribution to the WW II war effort. It was closed after the war, but was used by Rocketdyne for rocket motor production later (1960s, ?). It was shown as a Naval Weapons Reserve Plant on a 1988 Roads of Texas map, and on a 1998 Delorme Texas Road Atlas but not labelled. I believe it is currently in use by Texas A & M University. I believe that http://www.tsha.utexas.edu/handbook/online/articles/view/MM/hgm4.html will "take" you to McGregor and explain more and better about it than I've done. Bestes', Ben