⏵ Course guide · Interior Alaska winter endurance race
Chena River to Ridge sends runners, skiers, and bikers 55 or 26 miles out from Twin Bears Camp on maintained snowmachine trails east of Fairbanks, with real ascents and a hard 9 PM finish deadline for everyone. I will walk you through the course and checkpoints first, then give you a pacing and fueling plan for a winter endurance effort with a mandatory intermediate cutoff to respect. There are free calculators along the way to dial in your own numbers.
These facts come from the official Endurance North race page. Confirm the current-year registration date and any course updates before you commit.
Both distances start and finish at Twin Bears Camp on Chena Hot Springs Road, about 30 miles east of Fairbanks, on maintained snowmachine trails with grades rarely exceeding 10 percent.
The 26 mile covers the front section of the course with a 12-hour time limit and no intermediate checkpoint deadline to manage, just the course's own big ascents, fast downhills, and blind turns along with outstanding views of the local hills and the Alaska Range.
The 55 mile runs the full course with a 13-hour time limit and one hard intermediate deadline: you must reach the 26-mile checkpoint by 3:40 PM. That checkpoint effectively sets your pacing for the whole first half, since arriving late there ends your race regardless of how you feel.
Checkpoints sit at roughly mile 8 (Colorado Creek Cabin), mile 16 (Compeau Trail / Little Chena Dozer Line), mile 26, and, for 55-mile racers, a mandatory stop at Stiles Creek Cabin around mile 35. Each one offers hot and cold water, electrolyte drinks, hot chocolate, coffee, salty snacks, instant soup, and baked goods, real warm-food support for a cold day out.
For 55-mile entrants, the 3:40 PM checkpoint cutoff at mile 26 is the number that should shape your whole early pacing plan, not just something to check once you get there.
With an 8 AM start and a 3:40 PM checkpoint cutoff, 55-mile racers have 7 hours 40 minutes to cover the first 26 miles, an average pace requirement of roughly 17:40 per mile including any stops. Build a real pacing plan against that number rather than assuming you will have plenty of time, especially if fresh snow or cold temperatures slow the trail on race day.
Once you clear the mile 26 checkpoint, you still have roughly 5 hours 20 minutes to cover the remaining 29 miles and reach the 9 PM finish deadline. Do not spend everything getting to the checkpoint on time. A pace that is technically ahead of the front-half cutoff but leaves nothing for the second half is not actually ahead.
⏵ Free tools to plan your effort
The checkpoints give you real warm-food options, hot chocolate, coffee, and instant soup among them, but you still need a personal fueling plan for the stretches between them.
Hot chocolate, coffee, instant soup, and salty snacks at the checkpoints are a real advantage for morale and warmth, but the gaps between checkpoints, roughly 8 to 10 miles at a stretch, are long enough that you need your own carried fuel to stay steady in between.
Cold temperatures on Chena Hot Springs Road in early March can freeze exposed hydration lines and soft flasks. Carry fluid close to your body where possible, and know that checkpoint hot and cold water is there as a backup if your own supply freezes up.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight and your own finish-time target 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 training plan built around YOUR fitness and the pacing discipline that mile 26 checkpoint demands. Summit Line reads your real training, builds the durability a 55 or 26 mile winter endurance race asks for, and rehearses your fueling so race day is something you execute, not guess at.
The race itself describes the course as featuring big ascents, fast downhills, and blind turns on maintained snowmachine trails with grades rarely exceeding 10 percent, so this is not a flat cruise even though it is groomed. Add the winter conditions, a 13-hour cutoff, and a mandatory checkpoint at mile 26 you have to clear by 3:40 PM, and you have a genuine test of pacing discipline as much as fitness. The 26 mile is a more approachable winter endurance distance with a 12-hour window and no intermediate checkpoint cutoff to manage.
Both distances run on maintained snowmachine trails starting and finishing at Twin Bears Camp on Chena Hot Springs Road, about 30 miles east of Fairbanks. The race describes outstanding views of the local hills and the Alaska Range along the way. Checkpoints sit at roughly mile 8 (Colorado Creek Cabin), mile 16 (Compeau Trail / Little Chena Dozer Line), mile 26, and, for 55-mile racers, a mandatory stop at Stiles Creek Cabin around mile 35, each stocked with hot and cold water, electrolyte drinks, hot chocolate, coffee, salty snacks, instant soup, and baked goods.
The 55-mile race has a 13-hour time limit and a mandatory intermediate cutoff: you must reach the 26-mile checkpoint by 3:40 PM. The 26-mile race has a 12-hour time limit. Both distances share a hard finish deadline of 9 PM, since all racers must be off course by then.
You can run it. The race is open to foot, ski, and bike entrants on the same course, with one rule that matters if you are deciding your mode: you must finish using the same mode you started with, so you cannot swap from running to skiing partway through if conditions turn against you.
The race does not publish a mandatory gear list, but classic skis are recommended for the ski option and fat bikes are the suitable choice for the bike option. For runners, treat this like any serious winter endurance effort: dress in layers you can adjust on the move, carry your own fluids and fuel since aid station food is a supplement rather than your full plan, and bring navigation you trust, since the course covers real distance on trails that can look similar in low winter light. Post-race, Chena Hot Springs Resort and its thermal water are about 30 minutes away, worth planning for if you want a genuine recovery soak.
Registration opens in late 2026 with an exact date still to be determined; the field is capped at 100 entrants with a waitlist once full. Pricing before February 1, 2027 runs $90 for the 55 mile and $80 for the 26 mile, rising to $100 and $90 after that date. Registration is non-refundable and non-transferable, so confirm your distance and mode before you commit.
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<a href="https://runsummitline.com/guides/chena-river-to-ridge-endurance-race">The Chena River to Ridge Endurance Race course guide</a><iframe src="https://runsummitline.com/embed/race/chena-river-to-ridge-endurance-race" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Chena River to Ridge Endurance Race course guide by Summit Line"></iframe>This guide is independent and for planning only. The course details, dates, cutoffs, and checkpoint locations 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.
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