i thought they closed them after appalachian and opened them up in the mid/late 70s. like 77 officially? but there had to have been a ton of guys made on the low inbetween. i dont see how the whole 1960s goes by without anyone getting made. but they seemed like they were officially closed for 20 years. which is a pretty good length of a trial period for any guys who were young during the early 60s and needed to prove themselves