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Cool Moon Trail Races Course Guide

Cool Moon is a runnable, heat-soaked trail ultra in the Sierra foothills near Cool, California, on the same Olmstead Loop and Western States Trail country you know from Gold Country. You pick the 100K, 50 mile, or 25 mile, you stack the North and South loops, and you deal with the June sun. I will walk you through the course, then give you pacing and fueling strategy built for exactly those conditions, plus the free tools to dial in your own numbers.

⏵ Quick facts

Cool Moon at a glance

Date
Sat, June 13, 2026 (long-course day; annual, mid-June)
Location
Cool, CA, Sierra foothills near Auburn and Sacramento
Start / Finish
Cool Fire Station staging area (loop course)
Distances
100K, 50 mile, 25 mile (plus shorter Sunday races)
Elevation gain
About 9,000 ft (100K), 6,700 ft (50M), 3,350 ft (25M)
Course
Stacked 13.5 mile North + 11.5 mile South loops, single track and fire road
Start times
100K 5:00 AM, 50M and 25M 7:00 AM (Saturday)
Time limits
Generous published limits, confirm the current cutoffs on the race site

Note: the long-distance races (100K, 50M, 25M) run Saturday, June 13, 2026, with shorter races on Sunday, June 14. It runs every year in mid-June. The published time limits are generous but they show up differently across third-party sites, so always confirm the exact date, route, and cutoffs on the official Cool Moon race site before you plan your race.

The course

Cool Moon runs out of the Cool Fire Station staging area on a stacked loop format. You do a 13.5 mile North loop, then an 11.5 mile South loop, in that order, and you repeat them until you hit your distance. It threads single track and fire road through rolling oak woodland on the Olmstead Loop and Western States Trail network, and the high point is only around 1,500 feet. So this is a heat-and-rollers race, not an altitude race.

The North loop: down to the river and back

The 13.5 mile North loop runs counter-clockwise out of Cool, dropping down two miles of the historic Western States Trail before climbing Pig Farm trail toward the top of K2, then linking Olmstead sections out to the Ranch and onto back country single track toward the American River and the Salt Creek area, before grinding back up to Cool. On its own it carries roughly 2,200 feet of gain.

This is where the bigger climbs of the day live, the canyon descents toward the river and the climbs back out. Your legs are fresh on the early laps, and that is the trap. It is so easy to bomb the descents and hammer the climbs here, and then you pay for it in the afternoon heat. Run the North loop controlled and save something for later.

The South loop: rolling and runnable

The 11.5 mile South loop heads down Knickerbocker to Blue Oak, across the Olmstead connectors and Triple Creek, then south on Olmstead to the Rim Trail toward Pilot Hill, onto Catecroft and the hidden lake trails, and back through Knickerbocker to Cool. It is gentler, around 1,150 feet of gain, and a lot more consistently runnable.

Because the South loop runs so well, it is where you make up or lose time. The smart move is to settle into an easy, efficient rhythm here. The mistake is reading runnable as fast in the heat. You still have to ration your effort and your fluids so the exposed sections do not cook you before the next loop.

Heat is the real challenge

Cool sits in the Sierra foothills, and mid-June afternoons heat up fast, especially once you climb out of the shaded canyon onto the open oak-woodland and fire-road stretches. The race even has a reputation as a hot summer run. Heat, not the terrain or the altitude, is the number one reason people fade here.

Treat the hottest hours like a survival game. Keep your core temp down with whatever the aid stations have, ice, cold sponges, a soaked bandana or hat, drink to your sweat rate, and stay ahead on sodium. Then run again once the day cools off. And watch for poison oak along the single track.

Aid stations and cutoffs

The loops are covered by aid stations at spots like the Ranch, Knickerbocker, Pilot Hill, Catecroft, and the Cool staging area, and the staging area doubles as a natural lap hub for your drop bags and crew. Carry enough fluid between aid to get you across the exposed stretches in the heat.

The published time limits are generous, which fits the relaxed feel of the event, and the shorter Sunday races have no cutoff. The exact hours get listed differently across third-party sites, so check the current cutoff chart on the official Cool Moon race site and build in some margin so the afternoon heat does not put you behind late.

Pacing strategy for Cool Moon

A runnable, rolling, hot course rewards even effort and punishes anyone who treats the first loop like a road race. Pace by effort and by grade, and pace for the heat, not for the splits you would hit on a cool morning.

Pace the rollers by effort, not by clock

With constant little climbs and dips, your moving pace is going to bounce all over the place, and that is fine. Power-hike the steep canyon pitches and run the gentle grades and the flats. Trying to hold one minutes-per-mile number across rolling terrain is a fast way to spike your effort on every little climb and show up to the heat of the day already cooked.

Use our free grade-adjusted pace calculator to turn your flat fitness into honest effort targets for the rollers, so you actually know whether you can hold the vertical across multiple laps. Then learn to pace by feel with our guide to pacing an ultramarathon by effort.

Build your race around the heat

The whole game at Cool Moon is banking smart, controlled progress in the cooler early hours without overcooking, then surviving the hot middle of the day, then running again as it cools. The 5:00 AM 100K start is there for a reason, to get you down the trail before the worst of the sun. Nothing reckless up front, but use that cool window while you have it.

To set a finish goal you can actually hit, use our race time calculator, which folds the rolling vertical into a projected finish so you are not stuck on a flat-course guess. Then sanity-check that goal against a recent result with our race equivalent calculator before you commit to it.

Manage the laps mentally

The stacked-loop format cuts both ways. You always know the trail and you see your crew a lot, but you also keep passing the start area knowing you have to head right back out. Break the race into loops, run each one to its own plan, and do not sit there doing the math on the whole day while you are baking in the heat.

On the steeper canyon climbs, an efficient power-hike beats a labored run almost every time. If you are not sure when to hike versus run, or how to use poles on the pitchy sections, our guide to power-hiking and trekking poles will save you a ton of energy over the long day.

Fueling strategy for Cool Moon

A hot, all-day foothills effort makes fueling and hydration just as decisive as fitness. The June heat is the thing that wrecks most well-trained runners out here, so plan your sodium and fluid for it.

Carbs: ramp to the high end, on a trained gut

For something this long, aim for roughly 60 to 90 grams of carbohydrate per hour, leaning to the high end once your gut can 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 so 80 to 90 g/h feels normal, not like an experiment, by race day. Check our guides on how many carbs per hour for an ultramarathon and building a full fueling plan.

The heat makes all of this harder, because a hot stomach takes less and your appetite drops. That is one more reason to practice fueling in race-like warmth and to keep getting calories in through the hot, miserable hours, when your engine still needs fuel even though you do not feel like eating a thing.

Sodium and fluid: built for the heat

Out on exposed foothill single track and fire road in June, you sweat out a lot, so push your sodium up, roughly 500 to 800 mg per liter of fluid, and carry enough to get you across the hot, sun-baked gaps between aid stations. Cramping, a sloshy stomach, that wrung-out late-race feeling, that is usually a fluid and sodium problem, not a fitness problem. Our guide on how much sodium per hour for ultra running helps you find your number.

Dial in a plan with our free ultra fueling calculator. Put in your weight, your goal time, and the expected heat, and it spits out a carb, sodium, fluid, and caffeine prescription per hour built for the Cool Moon duration and conditions. Then go test it in training, ideally on a hot day.

⏵ Free calculators for this race

Run your Cool Moon numbers with our free, no-signup tools, then let Summit Line tie them all to your real fitness and this exact course. No fluff, just the numbers you need.

See all free running tools →

Train for it

Cool Moon rewards doing the specific work: the right volume for your distance, heat readiness, and a fueling plan you have actually rehearsed. These free guides cover the stuff that matters most here.

⏵ Train for Cool Moon

Get a race-day plan dialed to YOUR fitness and this exact course. Summit Line reads your actual training, builds a fueling and pacing plan around the Cool Moon rollers and the June heat, and tracks how your gut and legs handle the load, so race day is rehearsed, not guessed.

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Cool Moon Trail Races FAQ

How hard is the Cool Moon Trail Races?

It runs easy on paper and then quietly beats you up. The trail itself is friendly, a stacked set of well-marked loops on the Olmstead Loop and Western States Trail network near Cool, California, single track and fire road, no real altitude (you sit around 1,200 to 1,500 feet the whole time). What gets you is the mix of rolling, never-flat vertical and June heat out in the Sierra foothills, and the race kind of owns that, it has a name for being a hot summer run. The 100K stacks up roughly 9,000 feet of climbing across its loops, the 50 miler about 6,700 feet, the 25 miler about 3,350 feet. So the gain is real even though no single climb is a monster. Honestly though, if you manage the heat and pace the rollers it is very doable, and the published time limits are generous.

How much climbing is in the Cool Moon Trail Races?

Per the official race info, total gain is about 9,000 feet for the 100K, about 6,700 feet for the 50 miler, and about 3,350 feet for the 25 miler. None of it comes from one big mountain. It is a pile of short rolling climbs and canyon dips, because the course strings together a 13.5 mile North loop (about 2,200 feet of gain) and an 11.5 mile South loop (about 1,150 feet) that you repeat to hit your distance. The steepest stuff is dropping into and climbing out of the American River canyon sections. The gain sneaks up on you, so respect it on the second and third laps.

How should I fuel for the Cool Moon Trail Races?

Fuel for a long, hot, rolling day. Most people aim for 60 to 90 grams of carbohydrate per hour, leaning to the high end once your gut can take it, and you want your sodium up because June in the Sierra foothills gets hot and you sweat out a lot. Plan on roughly 500 to 800 mg of sodium per liter of fluid, and carry enough to get you across the exposed, sun-baked stretches between aid. The heat kills your appetite, so practice eating when you do not feel like it and keep the fluids steady. Our free ultra fueling calculator will build you a carb, sodium, and fluid plan per hour for your expected time and the heat.

What are the cutoffs for the Cool Moon Trail Races?

The race hands out really generous time limits, which fits the laid-back, finish-friendly vibe of the whole thing. There are separate limits for the 100K, 50 mile, and 25 mile, and the shorter Sunday races have no cutoff at all. The third-party listings disagree on the exact hours, and the limits are so lenient anyway, so just confirm the current cutoff chart on the official Cool Moon race site before you plan. And even with a forgiving limit, do not get lazy on the early loops in the heat. Keep some margin so the afternoon sun does not turn a comfortable pace into a death march.

Is the Cool Moon Trail Races at altitude?

No. This is a low-altitude foothills race. The Olmstead Loop and the Western States Trail terrain near Cool sit at roughly 1,200 to 1,500 feet, so thin air is just not a thing here. The challenge is heat, not altitude. That is good news if you live at sea level, you will not be gasping for air. But it also means your heat prep matters way more than any altitude prep. Train for warmth and sun, not elevation.

What is the course like at the Cool Moon Trail Races?

It is a stacked loop course out of the Cool Fire Station staging area. You run a 13.5 mile counter-clockwise North loop (down the historic Western States Trail, up Pig Farm and K2, onto Olmstead and back country single track toward the American River, then back to Cool) and an 11.5 mile South loop (Knickerbocker, Blue Oak, Olmstead connectors, the Rim Trail toward Pilot Hill, the hidden lake trails, back to Cool). You do North first, then South, and you repeat them until you hit your distance. It is flowy single track and fire road through rolling oak woodland, marked really well, with the steepest pitches down in the canyon sections. Watch out for poison oak and the afternoon heat on the open stretches.

This guide is for planning and training purposes and reflects publicly available information about the Cool Moon Trail Races. Race details, including the date, course, aid stations, and cutoffs, can change year to year, and third-party listings sometimes disagree. Always confirm the current specifics on the official Cool Moon race website before you train or travel.