Peter Achermann has not been forgotten.

Six years ago, Achermann, 82, left his home in Staples to run a few errands, and vanished. He had been making plans to speak at his granddaughter's wedding the following day.

Cass County Sheriff Tom Burch sent out another call for information Monday. Achermann was last seen on Friday, July 24, 2009, on Warner Road, by the Crow Wing River Bridge, between noon and 1 p.m. The next day, searchers discovered his car -- a light blue 1995 Chevrolet Caprice Wagon -- stuck in the mud on a dead-end road a few miles northeast of Staples.

Despite extensive searches and the offer of a $20,000 reward, no other trace of Achermann has been found. In a statement, Burch said his investigators continue to conduct interviews and follow leads, but have found nothing substantial.

"The family wants to thank the volunteers and the community for all their support," Achermann's son Franz said in a statement.“We are diligent about bringing Dad home and our work is not yet finished.”

Anyone with information, tips or leads on Achermann’s whereabouts is asked to contact the Cass County Sheriff’s Office at (800) 450-2677 or (218) 547-1424.