The following trails are groomed for fat biking in the winter. They are listed in order of difficulty, from the easiest to the most difficult.
(Current trail conditions):
Big Easy: 2.5 miles, easy, double track. The Big Easy is a beginner loop at Hwy OO. It is wide with virtually no hills and was built courtesy of the American Birkebeiner Ski Foundation. The trail begins just east of the Hwy OO trailhead. (Not yet available due to active logging operation.)
Hayward Hospital Gateway: 1.25 miles, easy, 100% singletrack. The Hospital Gateway Trail is the newest addition to the CAMBA trail system thanks to a partnership with the Hayward Area Memorial Hospital. Phase One, approximately 1.25 miles, was completed in 2017. It consists of a series of sweeping curves along a gentle hill and crosses several ski trails. Access: Northwest corner of the Essentia Clinic parking lot, off Hwy 77, a mile west of Hayward.
Cable Town Trails: 2 miles, easy, double track. The Cable Town Trails are a group of short, interconnected wooded loops separated by an open field. The main west loop is easy rolling. The east loop goes in and out of a small ravine. Snowshoe trails intersperse with the bike trails. Access: Cable Community Center.
Westside and Backside: 3 miles/6 miles round trip, intermediate, singletrack and ski trail. Westside and Backside are two parts of the same trail connecting the Birkie Start to Timber Trail. Westside begins on the east side of the Great Hall at the Birkie Start area, behind the propane tank, and runs south for almost 2 miles. Backside is shaped like a lollipop, with Westside meeting it at the top of the lollipop and the stick connecting to Timber Trail. The first part of Westside is the most technical, with a few short, steep climbs. The trail then transitions to ski trails until you reach the stick. The east side of the Backside loop is very hilly. The west side of the loop is fairly flat. The stick is moderately hilly. Please stay on the “bike lane” part of the trail on shared-use sections. Access: Birkie Start on McNaught Road.
Big Fat Loop (BFL): 14 miles, intermediate, singletrack, double track, snowmobile trail and road. The Big Fat Loop (BFL) is a winter-only trail using forest roads and two short sections of snowmobile trail to link Makwa and Seeley Pass to the Seeley Hills trails. It has some moderately technical singletrack sections and moderate climbing. Access: Hwy OO and Old OO. From Hwy OO, it rides best counter-clockwise, starting with Seeley Pass; turn left a few hundred yards past the Janet Road intersection; follow the signs across OO and through the woods until you reach Frindt Road; turn right on Frindt Road; turn left on Old OO and follow it to the Seeley Hills trailhead; follow the Seeley Hills trail to the southernmost part of the trail; turn left and follow the signs across Thannum Fire Lane and continue to Snowmobile Trail 31; follow the signs on the snowmobile trail for 1000 yards; turn left and follow the signs to Phipps Fire Lane; follow the signs to the right for 50 yards, then turn left and follow the Makwa Trail back to OO.
Mt. Ashwabay Trails: (Alternative map) 7 miles, intermediate, singletrack and ski trail. The trail has a gentle intermediate out and back section which accesses a more challenging singletrack loop. Expect sections of gradual climbing, rolling terrain, and a handful of challenging climbs. You will be rewarded with a one-mile long flowing descent back to the trailhead. Access: Look for a big red sign on the eastern edge of the Mt. Ashwabay Ski Area’s parking lot. Ride past the maintenance building along the powerline to Stick Up/Down. A $5 fee is required for non-pass holders. Pay at the fee box or chalet. Fees collected support grooming operations. Winter biking at Mt. Ashwabay is a collaboration between North Coast Cycling Association and Ashwabay Outdoor Educational Foundation.
Esker: (Winter map) 5 miles, intermediate, 95% singletrack, 5% road. Named for a glacial ridge, Esker is not very technical and is shorter than other area trails, but it has lots of climbing to make up for it. Parts of the trail are prone to drifting so be ready for that, especially on top of the esker. Take a moment to enjoy the outstanding view from the top!
Makwa: (Winter map) 4.5 miles each way, intermediate, 100% singletrack. Makwa is groomed only from the Hwy OO trailhead south, to where the Big Fat Loop joins it near Phipps Fire Lane. It has a few long climbs but they are not steep.
Seeley Pass: (Winter map) Up to 12 miles each way/24 miles round trip, intermediate, 100% singletrack. Seeley Pass is 24 miles long if you go all the way to the High Point and back. It is moderately technical with a significant amount of climbing. It crosses several fire roads with opportunities to bail out. Secondary trailhead on Boedeker Road.
Hatchery Creek: 8.9 miles with 1, 2, 4, 6, and 7 mile cut-offs, intermediate to difficult, 100% singletrack. Hatchery Creek is perhaps the second most technical trail being groomed in the area. This trail gets lots of foot/snowshoe traffic near the trailheads. Please be watchful for walkers and respect their right to the trail. Biking is not allowed on the groomed ski trails except for a few short portions near each trailhead.
Seeley Hills: 6 to 10 miles, intermediate to difficult, 99% singletrack, 1% ski trail. Seeley Hills is the most technical trail being groomed, with lots of hills and some off-camber sections. Access: Uhrenholdt Forest entrance on Hwy OO and ski trail entrance on Old OO. The Uhrenholdt access climbs the biggest hill in the trail system and returns on the fastest and perhaps steepest descents in the system. The Old OO access avoids the steepest hills. The trail is almost 10 miles long from the Uhrenholdt access and 7 miles long from the Old OO access if you skip the Uhrenholdt section. A bypass shortens the distance from either trailhead by about one mile and avoids the most technical sections (locally known as JT and Fawn Trail). Please stay on the “bike lane” part of the trail on shared-use sections.