Loppet Trails & Recreation

Fat-Tire Biking

Biking the mountain bike trails in winter

Fat-tire biking is an awesome way to enjoy miles of winter riding fun in Theodore Wirth Park. Our trails are multi-use trails, used by fat-tire bikers, snowshoers, and winter hikers.

The Loppet Foundation maintains three singletrack trails in North Wirth: Area 36, Conundrum, and 45 North. Biking in the winter on these trails requires is limited to true fat bikes. Bikes must have 3.7″ tires or more and less than 10 psi tire pressure.

For the most up to date Loppet trail information and conditions, check out our Trail Conditions & Maps page.


Approximately 1.25 miles of intermediate and advanced level single track that starts with one of the biggest climbs in the park. Test your bike handling skills on the downhill switchbacks and the big log ride and enjoy the return along Bassett Creek.  

Access this trail just north of the old golf chalet off of the parkway just before you head north over the Bassett Creek bridge. Two long boardwalks mark the start and finish of the trail and are visible from the parkway. 

45 North

Approximately 1.5 miles of intermediate level single track. This is our fast and flowing single track with plenty of rollers. When you get to the far north side of this trail you actually cross directly over the 45th parallel!  

Access this trail off of Theodore Wirth Parkway when heading north of the old chalet and just after you cross over the Bassett Creek bridge. It is on the west side of the parkway but the east side of Bassett Creek. 

Additional Fat Biking trails managed by MORC/MOCA (Minnesota Off Road Cyclists) are available in the park as well. Head to the MORC website or check the “MORC Trails” app for current trail information.

North Loop (Back 40):

Approximately 3.5 miles of single track, 0.5 miles are expert.

Accessible off of the Luce Line Trail that runs easterly from Theodore Wirth Parkway, just south of The Trailhead.

Back 40 Loop Map and Information »

South Loop:

Approximately 0.66 miles of single track.

Accessible from Theodore Wirth Parkway, just south of the railroad track bridge and from the south near Olson Memorial Highway.

South Loop Map and Information »

Glenwood Spur:

Just short of a one-mile loop.

Accessible from the Northwest corner of the Theodore Wirth Parkway and Glenwood Avenue and off the parkway’s paved trail 0.25 miles further north.

Glenwood Spur Map and Information »

Southwest Loop:

Approximately 1.9 miles of single track. 1.9 miles are intermediate difficulty.

Accessible by bike from the Southwest corner of the Theodore Wirth Parkway and Glenwood Avenue, and from the Northwest corner of Theodore Wirth Parkway and I-394

SW Loop Map and Information »

Brownie Lake Loop:

Approximately 1.5 miles of single track. 0.75 miles are intermediate to expert difficulty, 0.25 are expert difficulty, and 0.5 are extreme difficulty.

Accessible by bike from the Southwest corner of the Theodore Wirth Parkway and I-394.

Brownie Lake Loop is an advanced trail with steep rock climbs and descents, and technical features including drops. This trail requires expert skills to ride safely.

Brownie Lake Loop Map and Information »

Watch out for Fat Bike Nights at The Trailhead this season. Fat bikers may ride the snowmaking trails from 6pm – 9pm on select Friday, Saturday, and Sunday evenings when the trails are open.

Riders must buy an All-Access Ski Trail Pass in order to ride the trails. Note that riders who already have a pass for skiing may use the same pass for riding. Riding is ONLY allowed on Friday, Saturday, and Sunday evenings, and riders cannot ride on any other ski trails during fat-tire biking hours – or at any other time.

The Loppet Foundation reserves the right to shut down fat tire riding if conditions are not conducive.

Like all trail users, bikers must ride under control at all times, and respect other users – be they skiers or bikers. Bikers must follow the one way trail system at all times, and adhere to the following rules:

  • All trail users must purchase an All-Access day or season ski trail pass. Ski Trails are ONLY open to fat-tire bikers with passes on select Friday-Sunday nights 6-9pm.
  • Purpose-built snow bikes only! Tires must be wider than 3.7” and tire pressure must be less than 10psi, no exceptions. Standard mountain bikes are NOT ALLOWED.
  • Bikes and tires must be clean before entering the ski trails. Tracking of dirt debris, and/or lubricant from drivetrains will disrupt the snow deck and is therefore a barrier to entry.
  • Any fat-tire biker using the non-lighted portion of the course must ride with a headlight or light attached to the front of their bike.
  • Riders will be expected to stay as close to the edge of the deck OPPOSITE SIDE of the classic ski tracks as possible.
  • DO NOT ride on/over the classic ski tracks.
  • Bikers yield to all other users, Skiers don’t have brakes, so bikers are responsible for staying out of the skiers’ way. And watch skiers’ poles. They can be fragile and expensive and unpredictable – the skiers too.
  • On downhills, fast/sharp corners, or passing, bikers and skate skiers should share the trail.
  • DO NOT ride more than two abreast. Fat-tire bikers must ride single file when passing skate skiers – or classic skiers not in the track.
  • Be a good citizen. If the conditions cause you to leave ruts, exit the trail immediately – don’t just keep riding because the rules say you can. Spread the word about snow biking, make it fun, keep it safe.
  • Be an ambassador for the sport – stay polite, educate other bikers, discourage bad behavior, follow the rules, and we’ll all have a good time this winter.

Biking is allowed on paved and plowed bike paths, or on designated mountain bike trails only. Biking is specifically NOT ALLOWED in the Eloise Butler section of trails (sometimes referred to as southeast Wirth), or on any groomed ski trails.