Sure looks like a Sauger. And being in 1981 it would have to have been bred in Zoar. So where did the Sauger come from?
Almost every impoundment stocked with walleye ends up dumping walleye downstream somehow. The Lilli to Zoar transition was from a hurricane flood if I recall the history of that correctly.
Saltonstall dumps walleye into the outlet stream, same with the Saugatuck Res. in to the lower Saugatuck River.
Over in NY Sodom Res. dumps walleye into the lower Croton River and into the Diverting Res. Boyd's Corner Res. dumps them into West Branch Res.
Squantz into Candlewood, etc.