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Dick Collins Firetrails 50 Course Guide

The Firetrails 50 is one of the longest-running 50 milers in the country, a rolling out-and-back through the East Bay regional parks above Castro Valley. Runnable fire roads, redwood singletrack, real climbing without the altitude, and a late-September day that can turn warm on you. I will walk you through the course, then hand you pacing and fueling strategy built for those exact conditions, plus free tools to dial in your own numbers.

⏵ Quick facts

The Firetrails 50 at a glance

Date
Sat, September 26, 2026
Location
Lake Chabot Marina, Castro Valley, CA (East Bay)
Distances
Bay Ridge 100K · Firetrails 50 Mile · Golden Hills Marathon
50 Mile elevation gain
Roughly 7,800 ft of climb (sources cite about 7,800 to 8,500 ft)
50 Mile start / limit
6:00 AM start, 15.5 hour time limit
100K start / limit
5:00 AM start, 16.5 hour time limit
Marathon start / limit
7:00 AM start, 13.5 hour time limit
Qualifier / series
UTMB Index event; 50 Mile is part of the Pacific USATF Grand Prix

Note: distances, the exact course, aid stations, and cutoffs can shift year to year, and only the 50 mile elevation gain is consistently published. Always confirm the date, route, start times, and cutoffs in the official athlete guide before you plan your race.

The course

The Firetrails 50 starts and finishes at Lake Chabot Marina and runs an out-and-back through the East Bay regional parks, linking Anthony Chabot, Redwood, and Tilden along the ridgeline trails. It is mostly fire road and dirt road, roughly 70 percent, and stretches of redwood singletrack fill in most of the rest. The 50 mile carries about 7,800 feet of climbing, and you get views of Mount Diablo and San Francisco Bay out on the open ridges. The Bay Ridge 100K runs a longer out-and-back toward Rancho Laguna, and the Golden Hills Marathon takes a shorter loop.

Runnable terrain is the trap

This is not a high mountain 100. There is no altitude and there is no one decisive climb. The footing is smooth fire road and the grades roll instead of wall up, so you have almost no excuse to walk except on the steeper pitches. And that is exactly what makes it sneaky. It is easy to run the early rollers hard while you feel fresh, and then find out on the way back that those same hills quietly emptied your legs.

So treat the runnable ground with respect. Run the climbs only where the grade actually lets you, hike the steeper ramps with purpose to save something, and keep your early effort honest. The out-and-back gives you a built-in reality check, because you run the same hills home that you ran on the way out.

Rolling climbs, no flat to hide on

That roughly 7,800 feet of gain does not come from one big summit. It comes from constant, repeated rollers through the East Bay parks. There is almost no sustained flat where you can settle into a cruise, so you are always either going up or coming down. That nonstop up and down is the real signature of this course, and it punishes anyone who only trained on flat ground.

Because you climb and descend the same terrain twice on the out-and-back, vert-specific training pays off directly here. Time on rolling hills, both running them well and controlling the descents, is the most race-specific work you can do for Firetrails.

Heat and exposure on the ridges

Late September in the East Bay can hand you anything from cool coastal fog to a genuinely warm, sunny afternoon. A lot of the course is open ridgeline with little shade, so in a warm year the exposed midday sections are where people fade. The redwood groves give you some cover, but you cannot count on shade out on the open stretches.

Plan your hydration and sodium for the warm case even if the forecast looks mild, because afternoon heat on the return leg is the most common reason those runnable splits fall apart. Work your core temperature down at the aid stations, and keep fluids and electrolytes ahead of the heat instead of chasing it.

Aid stations and cutoffs

You are looked after by a string of well-stocked aid stations through the regional parks: fruit, chips, gels, potatoes and salt, soda, water, and sports drink, plus warm food like soup and quesadillas at the bigger stations later in the day. Drop bags and crew access are available at designated stations per the athlete guide.

The 50 mile gives you a 15.5 hour time limit from a 6:00 AM start, which averages out to a forgiving roughly 18:36 per mile. But the aid-station cutoffs along the way still apply. Pull the current edition from the official athlete guide and build your pacing plan backward from those checkpoint times, with a buffer, because the rolling terrain and the afternoon heat both work to slow you down on the return.

Pacing strategy for the Firetrails 50

A runnable, rolling out-and-back pays off patience and an honest early effort. Pace this one by effort and by grade, not by the flat-ground splits the smooth fire roads will tempt you into.

Run the first half like the second half is watching

The out-and-back does not forgive a hot start, because every hill you bombed on the way out is sitting there waiting for you on the way back. Run the front half a notch easier than feels natural, power-hike the steeper rollers, and keep your heart rate honest on the climbs. The people who even-split or negative-split Firetrails are almost always the ones who held back early.

Use our free grade-adjusted pace calculator to turn your flat fitness into honest effort targets for the rolling climbs, so you actually know whether you are pacing the vert in a way you can hold, or burning energy you are going to want on the return leg.

Set a realistic, vert-aware goal

Because it runs easy, you will be tempted to anchor your goal to a road or flat-trail pace. But roughly 7,800 feet of rolling gain quietly adds up. Build your finish target around the actual climbing instead of a flat estimate, and you will pace the day with margin rather than fading into the cutoffs.

Our vert-aware race time calculator folds the climbing into your projected finish, and our race equivalent calculator lets you sanity-check that 50 mile or 100K goal against a recent race result before you commit to a number.

Power-hike the steep ramps, run the rest

On a course this runnable, knowing exactly when to hike is a skill that buys you real time and real energy. Hiking the steepest ramps with a strong, purposeful stride is often barely slower than shuffling them, but it is far cheaper on the legs, and that keeps your running gears fresh for the long runnable stretches between the climbs.

Practice the run-hike switch on rolling terrain in training until it is automatic, and on race day you will spend your energy where it actually buys speed instead of grinding up every ramp.

Fueling strategy for the Firetrails 50

A long, runnable, often warm day burns calories fast, so fueling and hydration matter as much as fitness here. The easy terrain hides how much you are actually spending. So plan it on purpose.

Carbs: do not let the easy footing fool you

For an effort this long, aim for roughly 60 to 90 grams of carbohydrate per hour, pushing the high end once your gut is trained to handle it. Use a glucose-plus-fructose blend so you can absorb more than a single sugar lets you, and rehearse your exact hourly carb number on long training runs until it feels like nothing on race day.

Because the runnable terrain keeps your burn high, the classic Firetrails mistake is eating too little in the easy early miles when you feel great, and then bonking on the way back. Start eating early, stay on a schedule, and keep the calories coming even when the afternoon warmth kills your appetite.

Sodium and fluid: built for a warm afternoon

Out on the exposed East Bay ridges, a warm late-September day can run your sweat losses high, so bias your sodium toward 500 to 700 mg per liter of fluid and carry enough to cover the gaps between aid stations on the open stretches. Cramping, a sloshy stomach, that wrung-out late-race feeling, those are almost always fluid and sodium problems, not fitness problems.

Dial in your own plan with our free ultra fueling calculator. Enter your weight, your goal time, and the heat you expect, and it gives you a carb, sodium, fluid, and caffeine number per hour built for the Firetrails duration and conditions. Then go test it in training.

Train for the Firetrails 50

Free, in-depth Summit Line guides that map straight onto this race: the distance, the rolling vert, and the fueling that decides how your day goes.

⏵ Train for the Firetrails 50

Get a race-day plan dialed to YOUR fitness, this exact course profile, and your projected splits. Summit Line reads your actual training, builds a fueling and pacing plan around the Firetrails rolling vert and that warm-afternoon risk, and tracks how your gut and legs handle the load so race day is rehearsed, not guessed.

Dick Collins Firetrails 50 FAQ

How hard is the Dick Collins Firetrails 50?

It runs honest but it asks more of you than the numbers say. The 50 mile carries roughly 7,800 feet of climbing on an out-and-back through Lake Chabot, Redwood, and Tilden regional parks, mostly fire roads with some singletrack mixed in. There is no altitude and there is no one big monster climb. But the ground never stops rolling, so you get almost no flat to recover on, and a warm, exposed late-September afternoon can grind the back half right out of you. This is a classic NorCal finish, and it pays off steady pacing and clean fueling way more than it pays off raw climbing legs.

How much climbing is in the Firetrails 50?

Public course data puts the 50 mile at roughly 7,800 feet of climbing, and some sources go as high as about 8,500 feet, and because it is an out-and-back you climb and descend the same rolling hills twice. None of it is a high summit and none of it is one decisive climb. It just comes at you in steady, repeated fire-road rollers through the East Bay parks. The Bay Ridge 100K stacks on even more total climbing over its longer out-and-back, and the Golden Hills Marathon runs a shorter loop. Always go confirm the current course profile on the official race site.

How should I fuel for the Firetrails 50?

Fuel it like the long, rolling, warm day it can be. Most runners aim for 60 to 90 grams of carbohydrate per hour, pushing the high end once the gut is trained for it, and a sodium concentration around 500 to 700 mg per liter of fluid, leaning higher if the late-September heat shows up on the exposed ridges. The course runs easy, so your hourly burn stays high the whole time. Do not let that smooth footing trick you into eating too little early. Our free ultra fueling calculator gives you a carb, sodium, and fluid plan per hour built for your expected time out there and the conditions.

What are the Firetrails 50 cutoffs?

The 50 Mile starts at 6:00 AM with a 15.5 hour time limit. The Bay Ridge 100K goes off earlier at 5:00 AM with a 16.5 hour limit, and the Golden Hills Marathon starts at 7:00 AM with a 13.5 hour limit. That 50 mile limit works out to roughly 18:36 per mile on average, so the final cutoff is forgiving. But the aid-station cutoffs along the way still apply. Pull the current edition from the official athlete guide and build your pacing plan around those checkpoint times, because the rolling terrain has a way of quietly putting you behind.

Is the Firetrails 50 a Western States or UTMB qualifier?

All of the Dick Collins Firetrails races are UTMB Index events, which feeds your UTMB qualifying and ranking record, and the 50 mile is part of the Pacific USATF Grand Prix. Whether a given distance counts as a Western States qualifier can move year to year, so check the current status on the official race site and the Western States lottery qualifier list before you bank on it. Either way, finishing one of the longest-running 50 milers in the country stands on its own.

What is the terrain like on the Firetrails 50?

It is mostly fire road and dirt road. Public surface data has it at roughly 70 percent dirt road, around 24 percent singletrack, and a small slice of pavement. It runs through the East Bay regional parks, redwood groves and open ridgeline, with views of Mount Diablo and San Francisco Bay. The footing is smooth and runnable, not technical, and that is exactly why pacing discipline matters here. There is barely a reason to walk except on the climbs, so it is easy to run the rollers too hard early and pay for it late.

This guide is for planning and training purposes and reflects publicly available information about the Dick Collins Firetrails 50. Race details, including the date, distances, course, aid stations, and cutoffs, can change year to year. Always confirm the current specifics in the official athlete guide before you train or travel.