⏵ Course guide · Marin winter trail race
Inside Trail Racing's Peacock Gap Trail Run twists over China Camp State Park's peak with views of Mt. Tam, San Pablo Bay, and San Francisco Bay, up to a 19.5-mile 30K with about 2,735 feet of gain. I will walk you through the course first, then give you a pacing and fueling plan built for an early December day in Marin. There are free calculators along the way to dial in your own numbers.
These facts come from the official Inside Trail Racing event page. Check the current year details, cutoffs, and aid stations before you commit. Race logistics change year to year.
China Camp was once a thriving Chinese shrimp-fishing settlement and is now a popular state park, its extensive trail network climbing over a peak with views out to Mt. Tam and two bays.
Each distance opens with roughly a mile and a half of easier running before a nice punch of a climb kicks in, leaving plenty of room afterward to push the pace or settle in and hike while taking in the wild turkeys and sounds of the surrounding woods.
The courses wind along thick forests before descending out into open trails on the San Pablo Bay side of the park, a real shift in feel over the course of a single race. Twisting singletrack carries you up and over the peak between the two.
Inside Trail Racing describes this course as relatively fast, but the punchy climb starting at mile 1.5 still deserves respect before you settle into rhythm.
A grade-adjusted pace target for the climb beginning 1.5 miles in gives you an honest number for that section, rather than pacing off how fresh your legs feel in the opening mile before the grade kicks in.
A race-time calculator built around your goal for the 30K or Half gives you a target you can check against the 6-hour limit, but with a course this fast and a window this generous, there is real room to run a controlled, enjoyable effort rather than racing the clock.
⏵ Free tools to pace this course
Early December in Marin County tends to run cool and sometimes damp, which changes fueling and hydration needs from a summer race.
Aim for roughly 45 to 75 grams of carbohydrate per hour on the 30K. Because the course is relatively fast and runnable, you should be able to eat and drink through most sections without breaking stride much.
Sodium in the 300 to 500 mg per liter range is usually enough given the cooler December conditions, since sweat losses typically run lower than on a warm-weather race.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a cool December Marin day with the free ultra fueling calculator. Browse the rest of the free running tools at the tools hub.
⏵ Train for it with Summit Line
Get a race-day plan built around YOUR fitness, this exact China Camp State Park course profile, and your projected splits. Summit Line reads your real training, builds a plan for punchy, technical singletrack, and rehearses your fueling so race day is something you execute, not guess at.
It is a relatively fast course by Marin standards, with a nice punch of a climb beginning 1.5 miles into every distance, leaving plenty of room after that to push it or hike and enjoy the scenery. The 30K covers 19.5 miles with about 2,735 feet of gain, and the 6-hour time limit gives real margin for the distance.
The 30K carries about 2,735 feet of elevation gain over 19.5 miles, roughly 140 feet per mile, a moderate ratio for a Marin County trail race. The course climbs up and over the park's peak via twisting singletrack, then descends into open trails on the San Pablo Bay side.
An early December race in Marin County usually means cool, sometimes cold and damp conditions, so plan your fueling and layering for a winter trail day. Aim for roughly 45 to 75 grams of carbohydrate per hour on the 30K, and sodium in the 300 to 500 mg per liter range given the cooler conditions. The course is relatively fast, so you can generally eat and drink through most sections without losing much time. Build your numbers with the free ultra fueling calculator before race day.
The 30K and Half Marathon both carry a 6-hour time limit from their 8:30 AM start, and all runners must be off the course by 2:30 PM. Given the relatively fast, runnable nature of the course, this window is generous for most trained trail runners.
China Camp was once a thriving Chinese shrimp-fishing settlement and is now a popular state park for boaters, runners, hikers, and mountain bikers. An extensive trail network greets runners with views of Mt. Tam, San Pablo Bay, and San Francisco Bay as the course twists over singletrack, climbing up and over the park's peak before descending into open trails toward San Pablo Bay, with thick forest sections and resident wild turkeys along the way.
Yes. Inside Trail Racing calls China Camp "a rare locale for a running race," and the relatively fast, well-marked course with a generous 6-hour window makes it approachable for a newer trail runner. The 10K is an especially good low-commitment way to experience the park's views and terrain before stepping up to the Half or 30K.
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<a href="https://runsummitline.com/guides/peacock-gap-trail-run">The Peacock Gap Trail Run course guide</a>This guide is independent and for planning only. The course details, dates, cutoffs, and aid stations come from public sources and can change year to year, so confirm the current specifics with the official race before you register or run. The fueling and pacing advice is general and not medical advice.