Last Friday skaters and officials from Mississippi Valley Mayhem helped Rochester, Minnesota’s new roller derby league in a mixer style bout with other leagues participating in the event. Harbor City Roller Dames out of Duluth, Chippewa Valley Roller Girls out of Chippewa Falls, Wisc., Moose Lake Mafia out of Moose Lake, Minn., S.C.A.R. Dolls, out of St. Cloud, and your very ...