Digger Wells was a resident of Sioux Falls, SD.
When Sam and Dean arrived in Bobby's hometown of Sioux Falls to investigate the recent death of Benny Sutton, they interviewed Digger Wells. He reported that on the night Benny was killed, he saw Clay Thompson climb into Benny's trailer through the window. They verified Digger was aware Clay Thompson had been dead for five years. When asked if he knew why Clay, dead or alive, would have any reason to want to kill Benny, he informed them Benny was the one who killed Clay in the first place, by shooting him in the back in a " so-called hunting accident". He calmly suggested Clay returned "to get a little payback."
When Sheriff Mills (referred to by Digger as "Fargo") interrupted their interview, Digger smugly informed her the 'agents' believed his statement. When she subsequently exposed the Winchesters and Bobby as pretend agents, she informed them any business they were conducting with Digger was to end immediately.
Despite a mild dispute with Dean about whether or not he was allowed to pick his own nickname, the Winchesters found Digger to be credible and relayed his statement to Bobby. He disagreed with them, and declared Digger to be a drunk. He told them he'd already checked out the Sutton case and found nothing there, despite Digger's account. This turned out to be untrue, as Bobby had by then realized the rising of Sioux Falls' dead was an apocalyptic occurrence brought on by the Horseman, Death, as foretold in the Book of Revelation.
Later, Sam found out from another citizen that Bobby was considered the town drunk, not Digger.