The 200-mile Mt. Tam Double Century is now open for registration. Register early to secure your spot. There is a 300 rider limit.
If you register before July 12 (cutoff subject to change), you will receive free concierge mailing of your registration packet about 2 weeks before the event. Skip check-in lines and head straight to the starting line!
If you register for the Double Century after the cutoff date, you will be need to check-in at the registration booth before riding.
Updates for 2018
The course is subject to change at any time. Please carefully read the course description in your registration packet. Use only official maps and cue sheets.
Check back here often for updates on the routes, maps and other important information.
Registered riders will receive updates via email.
Follow us on Facebook and Twitter for quick updates.
- There is a mandatory mass start at 5:00 AM. No one may start before or after that time.
- If you received your packet in the mail, head straight to the start line.
- If your need to pick up your packet or transfer a registration, visit the registration booth between 4:00 and 4:45 AM.
You are not permitted to start riding before 5:00 AM. NO EXCEPTIONS.
You MUST check in at all check points: (checkpoints will be published when the route is finalized)
Checkpoints are identified on the route map and cue sheet and Ride with GPS.
If you fail to sign in at checkpoints, you will get a DNF (Did Not Finish) and will not get Triple Crown Credit. No exceptions.
Bib numbers will be recorded at checkpoints.
Failure to sign-in at checkpoints will result in a DNF. Check the open/closed times.
- Bay Hill/Coleman loop closes at 3:00 PM. for all Double Century riders. NO EXCECPTIONS
- Course closes at 10:00 PM.
- If you ride slower than 11.5 mph average, you may not make the Coleman Valley Cutoff. You may bail out onto the Classic Century course. If you bail out or need SAG, you will get a DNF.
- The Mt. Tam Double Century will begin at 5 AM in the dark and could, depending on your speed, potentially end in the dark.
- You MUST have working lights for the start of the Mt. Tam Double Century. No exceptions. If you do not have lights, you will get a DNS (Did not Start)
- You MUST use lights after 8:00 PM.
Lights & Drop Bags
The Marin Cyclists will provide paper bags and marker pens for you to drop your lights and other gear and have them forwarded for later pickup.
Any bags not picked up as the course closes will be SAGed to the finish. Bags not picked up after the event will be returned to riders via mail ($10 fee).
Aero bars are permitted but not recommended. Please do not use aero bars when riding in pace lines.
You will receive a full-color, water-resistant map with cue sheet in your rider packet. Ride with GPS will also be available closer to the start date.
The MTDC begins on flat-to-rolling terrain before a 1.4-mile, 430-foot climb to the Big Rock summit of Lucas Valley and a thrilling descent through the redwoods into the ranches and grasslands of West Marin. Here the route parts ways with the other courses, winding south and east to the town of Fairfax and the ascent to the top of Mount Tamalpais (Tam), which begins on Bolinas-Fairfax Road. The narrow and twisting road levels out as it approaches a golf course and begins to climb again to the top of Pine Mountain, where you will find the first rest stop.
From Pine Mountain, the road descends in a series of tight turns with a decreasing radius to four miles of rollers ending at a dam at Alpine Lake. A three-mile ascent takes riders onto Ridgecrest Road, which offers sweeping views of the Pacific Ocean and golden grass hillsides for six miles of rollers, some with challenging grades, up to the top of Tam. At the very top is a checkpoint, the turnaround, and fantastic view.
You will then descend three miles, taking care to avoid riders finishing their climb to the top of Tam. You will then continue descending south to Pantoll and onto Panoramic Highway—both roads have sharp technical turns that require extreme caution.
Here the course changes from previous years and you will continue on Panoramic all the way to Hwy 1 at Stinson Beach.
You will turn north on Highway 1 just before the town of Stinson Beach, where you will find the second rest stop at the Stinson Beach School. You will continue on, passing the Bolinas Lagoon toward Olema and into Pt Reyes Station, where you will find the third rest stop. The course then continues north on Highway 1 and then onto Point Reyes/Petaluma Rd, following the flat creekbed inland to Platform Bridge Road, where you will make a right turn to the second checkpoint. You will then travel over to Sir Francis Drake Blvd and up and over the hill to Olema and back into Pt. Reyes Station. We repeat this part of the course to Platform Bridge, this time making a left onto Point Reyes-Petaluma Road and traveling inland past the Nicasio Reservoir. After a short climb and gentle descent past the Marin French Cheese Factory, the course continues toward Petaluma, site of the fourth rest stop . Leaving Petaluma, you will find the entrance of beautiful Chileno Valley Road, which takes a left turn on Tomales-Petaluma Road. The course continues to Highway 1 and the small town of Tomales. At the town center, the course turns left on Dillon Beach Road and continues to Valley Ford-Franklin School Road and a right turn on Highway 1 (away from Bodega), taking you to Valley Ford, site of the fifth rest stop and third checkpoint.
The course continues west on Bodega Highway to Bay Hill Road, which offers a grand view of the Pacific Ocean from the crest. A quick descent on rough road leads to some highly scenic miles of coastline before the route turns onto Coleman Valley Road and a long and steep climb with false summits and stunning views.
At the top of the Coleman Valley Loop, you will find the fourth checkpoint in small rest stop stocked with water, Gatorade, and energy supplements (gels, bars, etc). A 400-foot descent leads to yet another climb and a long, technical descent on Joy Road. USE EXTREME CAUTION on this winding and potholed stretch, which eventually leads to wide-shouldered roads and the sixth rest stop in Valley Ford.
The ride continues over scenic and sparsely traveled roads to the short but steep Middle Road climb, with another thrilling descent to the S curve at Whittaker Bluff. It then crosses over Highway 1 to Fallon Two Rock Rd. which you will follow to a right turn at Alexander Rd. and then a left back onto Tomales-Petaluma Rd for the trip back down Chileno Valley Rd. A rest stop awaits at the historic Laguna School before you climb back over the Wilson Hill to Hicks Valley Rd. USE EXTREME CAUTION WHEN DESCENDING. THERE IS A SHARP LEFT TURN AT THE BOTTOM OF THE HILL.
The route continues along the rolling hills of Hicks Valley Road before turning west on Pt. Reyes-Petaluma Road, taking riders past the Cheese Factory to a slight climb and a very fast descent to Nicasio Reservoir and Nicasio Valley Road. A relatively flat stretch lead to the fifth and final rest stop at the Nicasio Schoolhouse.
A few miles later, riders begin the climb back up Lucas Valley Road to Big Rock. Riders should exercise caution on the DEMANDING DESCENT FROM BIG ROCK AT LUCAS VALLEY ROAD. This descent has several sharp left-hand turns with a decreasing radius. The remainder of the route is almost all downhill to the finish.
Rest Stops & Rest Stop Food
If you need a particular item or drink, please bring it yourself. We cannot guarantee availability and we work hard to avoid food waste.
- For the Mt Tam Double Century riders only, each rest stop will have the normal fare, as well as Hammer Gel (bring your own flask) and Sustained Energy (SE).
- There will be sandwiches and/or burritos available at the Valley Ford Rest Stop for the Double Century riders.
- Some sandwiches and burritos MAY be available at Petaluma, however, this is not guaranteed.
SAG and Course Marshals
Course Marshals are only on the Classic Century sections of the DC course. There will be SAG vehicles on the entire DC course. Because it's a long course and the SAGs become very spread out as the day progresses, response times may be long.
Check-In at Finish
The official finish is at the check-in table located at the Start/Finish line. You MUST check in, even if you SAG in or DNF. We do not want to continue searching for you on the course. If uou do not check in, you many not be allowed to participate in future Mt Tam Double Century events.
Most of the Marin Century fanfare wraps up around 6:00 PM. We will have a hot meal for DC riders who arrive after 6:00; however, certain menu items may not be available.
Ride Time Results
We will post ride times on our website a few days after the event. We will announce the posting on Facebook and Twitter. Follow us for updates and news before the event.
Jerseys can be preordered during registration, added after registration, or purchased after the ride.
You will only receive your jersey if you finish the Mt Tam Double Century, your jersey will be mailed to you (they will not be available at the finish line.
If you receive a DNS or DNF, you will receive a refund for your preordered jersey.
DC Volunteers and Triple Crown Volunteer Credit
The Marin Century and Double Century are organized and run entirely by volunteers. We love our volunteers, and always appreciate those with riding experience. You know the challenges cyclists face and what they appreciate!
DC riders may earn Triple Crown Volunteer Credit for volunteering at the Marin Century.
Volunteer opportunities that specifically support the DC are available here.
Other volunteering opportunities are also available here.
Volunteers are welcome to ride the Workers Ride, which includes a Double Century. The Double Century Workers Ride qualifies as a Triple Crown event. Registration for the Worker's ride will open on August 5. Please see the Calendar on our website to register.
THERE IS A 24 HOUR TIME LIMIT FOR THE DOUBLE CENTURY ON THE WORKERS RIDE
California Triple Crown
Click here for more info on the CA Triple Crown