SGRAIL Marin (formerly Marin County Triathlon)
San Rafael (McNears Beach Park), United States · October · Independent (SGRAIL series; Marin Endurance Festival weekend)
Latest edition: Rebranded as SGRAIL Marin; 2026 edition ran Sat 3 Oct 2026 as Olympic and Olympic relay only (the April sprint/Olympic format of 2025 is gone). No 2027 date published yet. Earlier names: Marin County Triathlon, Marin Endurance Festival.
Why people love it
- Olympic in San Pablo Bay below China Camp State Park: 1,500 m (0.93 mi) swim, 40 km (24.9 mi) bike.
- Road, gravel and mountain bikes are all welcome on the bike course.
- Relay option splits the 1,500 m (0.93 mi) swim, 40 km (24.9 mi) bike and 10 km (6.2 mi) run.
- Optional trail half marathon the next day for a two-day weekend.
Watch out for
- The sprint is gone: only Olympic and relay ran in 2026, and no 2027 date is posted.
- Strong tidal current in the bay; one year the swim was cancelled over water quality.
- Mandatory foot-down on the steep Cantera Way descent, or you are disqualified.
- Swim exit cutoff is 1 hour after wave start and the bike turnaround closes at 11:45.
- Only two athlete accounts exist, one from 2011.
Race
How racers feel about it, how well it is run, and how it treats a first timer. Counts for 30% of the overall score.
Toughness: Tough
- Racer satisfactionLoved3.5
Only two thin reviews found; a 900+ field in 2011 and a Triathlete 2025 best sprint/Olympic listing; swim cancelled once for water quality. · Low confidence
- OrganizationWell run3.6
The swim cancellation was announced the day before; only two accounts exist. · Low confidence
- First timer friendlyDoable3.0
Olympic only now: 1,500 m (0.93 mi) tidal bay swim and a 40 km (24.9 mi) bike with a mandatory foot-down descent. · Low confidence
Course traits, not part of the score
- PR potentialAverage2.8
Steep Cantera Way climb and descent with a forced foot-down, four bike loops, tidal swim; elevation not published. · Low confidence
Swim
Wetsuit odds, water temperature, calm, and the experience of the start. Counts for 16% of the overall score.
- Wetsuit legalUsually4.2
Bay likely 14 to 17 °C (57 to 63 °F), well under the USA Triathlon limit of 25.6 °C (78 °F); rule not published. · Low confidence
- Water temperatureAcceptable3.0
Estimated 14 to 17 °C (57 to 63 °F) in April and October; not published. · Low confidence
- Calm waterSome chop3.0
Protected bay, but 2011 winner reported strong current and the course shifts with tide. · Low confidence
- Swim easeModerate3.2
Three-buoy triangle over 1,500 m (0.93 mi), waves every 5 minutes; current can push. · Low confidence
- Swim experienceFine3.0
Bay views and wave starts, but murky bay water and a history of failed water-quality tests. · Low confidence
- Swim supportGood3.5
SF Swim Club manages the course; waves every 5 minutes; 1-hour swim cutoff. · Low confidence
Bike
Road surface, closures, scenery and wind. Counts for 18% of the overall score.
- Road surfaceMixed3.4
County roads; gravel and mountain bikes are welcome, hinting at variable surface; no reports. · Low confidence
- Road closuresPartly closed3.0
Not stated; cars barred from the park 08:30 to 13:00 but the bike roads are county roads. · Low confidence
- Bike sceneryBeautiful3.8
China Camp State Park roads sound scenic, but no athlete has described the ride. · Low confidence
- WindSome wind3.0
Open bay shore; no wind reports. · Low confidence
Course traits, not part of the score
- Bike speedAverage3.0
Four loops with a steep start climb and turnarounds; elevation not published. · Low confidence
- Bike flatnessRolling3.1
Rolling shoreline road to China Camp plus the Cantera Way climb; 40 km (24.9 mi), gain not published. · Low confidence
- Bike simplicitySome technical parts2.8
Mandatory foot-down on the steep Cantera Way descent, repeated turnarounds and four loops. · Low confidence
Run
Crowds, aid stations, conditions underfoot and scenery. Counts for 13% of the overall score.
- Crowd supportDecent2.8
Out-and-back road run away from the beach; spectators mainly at the finish. · Low confidence
- Aid stationsStandard3.4
Aid at the Main Drive turnaround of the 10 km (6.2 mi) run; no wider reports. · Low confidence
- Run sceneryBeautiful3.6
Road run past the bay; no athlete has described the views. · Low confidence
- Run conditionsModerate3.2
Road run, mixed shade, mild October conditions. · Low confidence
Course traits, not part of the score
- Run flatnessRolling3.0
Climb up Cantera Way out of T2, then rolling out-and-backs; gain not published. · Low confidence
Conditions
Air temperature, how predictable the weather is, setting, and spectating. Counts for 13% of the overall score.
- Air temperaturePleasant4.2
Early October San Rafael about 12 to 24 °C (54 to 75 °F), dry. · Medium confidence
- Weather reliabilityReliable3.8
Dry season, but autumn heat and smoke are possible; rain or shine. · Low confidence
- Venue beautyLovely4.1
San Pablo Bay shore and park setting; a 2011 winner called the swim beautiful. · Medium confidence
- Spectator friendlySome viewpoints3.2
Beach finish; bike and run go out of sight on loops. · Low confidence
Course traits, not part of the score
- Low altitudeSea level5.0
Sea level, about 5 m (16 ft). · Medium confidence
Stay and travel
Hotels, walkability, getting there, and the town around the race. Counts for 10% of the overall score.
- Hotel availabilityBook early3.4
Marin and SF Bay Area lodging is plentiful but busy in autumn. · Low confidence
- Hotel valueNormal2.6
Marin County hotels are expensive. · Low confidence
- WalkabilitySome driving3.0
Park with limited road access; cars barred from the park 08:30 to 13:00. · Low confidence
- Travel easeEasy4.0
SFO about 40 km (25 mi), Oakland about 45 km (28 mi). · Medium confidence
- LogisticsSome complexity2.8
Bib pickup Thursday or Friday, no Friday bike drop, separate T1 and T2 (T2 at the foot of Cantera Way), same-day gear pickup. · Low confidence
- Town and foodGood4.0
San Rafael and Mill Valley restaurants nearby. · Low confidence
Key facts
- Location
- San Rafael (McNears Beach Park), California, United States
- Typical month
- October
- Latest or next date
- 3 October 2026
- Organiser
- Independent (SGRAIL series; Marin Endurance Festival weekend)
- Entry fee
- About $200
- Distances
- 1.5 km (0.9 mi) swim, 40 km (24.9 mi) bike, 10 km (6.2 mi) run
- Cutoffs
- Swim exit within 1 h of wave start
- Swim venue
- San Pablo Bay off McNears Beach Park (bay)
- Water temperature
- 14–17 °C (57–63 °F)
- Wetsuit
- Not stated by organiser; USA Triathlon rule applies
- Swim start
- wave (every 5 minutes)
- Swim laps
- 1
- Bike laps
- 4
- Key climbs
- Cantera Way (start of bike, steep descent back to T2)
- Run laps
- 2
- Run shade
- mixed
- Air temperature
- 12–24 °C (54–75 °F)
- Humidity
- low to moderate
- Altitude
- 5 m (16 ft)
- Nearest airport
- San Francisco International (SFO), 40 km (25 mi) away
- Where to stay
- San Rafael, Novato, Larkspur
- Booking
- Bib pickup Thursday 15:00 to 19:00 at Sports Basement Novato and Friday 15:00 to 18:00 at the park. No transition access or gear drop-off Friday; bikes and gear go in on race day and must be collected the same day. Cars barred from park from 08:30 Saturday until 13:00.
What racers and reviewers say
- Triathlete (local athletes win Marin County Triathlon)Raced 2011 · article · Positive
Race report from the early November 2011 edition at McNears Beach, a two-day event with more than 900 entrants including elites. The overall winner described good conditions and a beautiful swim, but with a pretty strong current. Dated, but it shows the race has long had a large field and a tidal swim.
“the current was pretty strong”
- BibRave (Marin Endurance Festival reviews)aggregator · Mixed
A participant says organisers emailed the day before that McNears Beach had failed a county water-quality test, so the swim was cancelled. The writer felt both relief and disappointment and chose to race the bike and run anyway. Shows the race handles a cancelled swim with early notice but also that bay water quality is a real risk.
Raced SGRAIL Marin (formerly Marin County Triathlon)? Your notes on the course, conditions and logistics help the next athlete decide.
Sources
Pages we used for facts and ratings. See how we rate.
Training for SGRAIL Marin (formerly Marin County Triathlon)? Moku Coach builds your plan around race day.