Mississippi Valley Mayhem will be opening up season 6 in the Valley of the Living Dead: Survival of the FittestĀ as we take on Wisconsin River Valley Rollergirls on May 31st, 2014 at the Onalaska Omni Center. Doors open up at 6:00pm and action gets underway at 7:00pm. Tickets are $9 for adults, $1 off if ...