The entire dunefield and most of the park and preserve's mountain trails are within federally designated wilderness, where mechanized equipment is not permitted. While regular bicycling and mountain biking options are very limited, fat bikes (mountain bikes with extra wide tires for sand) are permitted on the Medano Pass Primitive Road, a challenging road with extended sections of sand, creek crossings, and rocks. The road is open to fat biking both for day use and for overnight camping in Medano Canyon.
Check current road conditions before riding; if sand gets soft during dry times, travel may not be possible.
You will be sharing the single lane road with 4WD vehicles, some traveling at higher speeds in order to make it through sandy sections. For your safety, listen and watch carefully for vehicles as you ride.