I love him to death but I need to call out Ernie Terrell from Norristown, PA. Ernie was a monster in high school 100/200/400. I remember him splitting 45. on the anchor leg at Penn as a senior.
Played football sparingly at Penn State and eventually quit. By the time he made the decision to run rather than play FB, the poor training (in FB & part-time track) at PSU has already done its damage. He never ran even close to his potential. Got worse the longer he was in school.
Tom Fischer from NJ also comes to mind. High school stud. Went to school down South (Auburn?, Clemson?) for a semester and ran o.k. in XC. Came home (attended Monmouth College when it was like an extension of high school) and was never at the same level again.
Murad Campbell (NJ) anyone? Matt Elmuccio (NJ) perhaps?