The Central Oregon Trail Alliance (COTA) grooms a network of trails for fat bikes at Wanoga Sno-Park. The USFS doesn’t currently restrict fat bikes at Meissner Sno-Park, but in the interest of providing a variety of different recreation opportunities and sharing our public lands, COTA, Meissner and the USFS all strongly encourage fat bikes to ride at Wanoga rather than Meissner.
More info: https://www.cotamtb.com/winter-fat-bike-trails-grooming--map.html