Summit Line

⏵ Course guide · Central Oregon timed race

Suttle Lake Trailfest Course Guide

Suttle Lake Trailfest is a mellow, timed festival, run as many 3.6 mile loops as you can in 24, 12, or 6 hours around Suttle Lake near Sisters, Oregon, with only about 110 feet of gain per lap and free lakeside camping for the weekend. I will walk you through the loop and the timed format first, then give you a pacing and fueling plan built for accumulating laps rather than chasing a finish line. There are free calculators along the way to dial in your own numbers.

⏵ At a glance

Suttle Lake Trailfest quick facts

Date
Saturday, October 24, 2026, 8:00 AM start
Location
South Shore Campground, Suttle Lake, near Sisters, Oregon
Format
Timed: 24 hour, 12 hour, and 6 hour races, all on the same loop
Loop
3.6 mile loop around Suttle Lake, about 110 ft of gain per loop
Distance
Open-ended: run as many 3.6 mile loops as you can within your chosen window
Camping
Free camping at South Shore Campground for the weekend
Organizer
Alpine Running (also runs Run The Rock, Smith Rock Classic, Three Sisters Skyline, Elkhorn Crest 50)
Cutoff
Race ends at the close of your chosen window (24 hr, 12 hr, or 6 hr); no per-loop cutoff published

These facts come from the official Alpine Running event page and its linked UltraSignup listing. The timed format has no fixed finish distance, so confirm the current race-day details before you commit. Race logistics change year to year.

The loop and the format: pick your window

Forget a fixed distance. At Suttle Lake you choose a window, 24 hours, 12 hours, or 6 hours, and simply run the same 3.6 mile lakeside loop as many times as you can before that window closes. The loop carries about 110 feet of gain, a soft, mostly flat profile that makes the format, not the terrain, the real variable.

The 3.6 mile loop: short, soft, and repeatable

Every distance shares the same loop around Suttle Lake, about 3.6 miles with roughly 110 feet of gain, a gentle profile compared to Central Oregon's mountain races. That softness is a feature: it lets you settle into a genuinely repeatable rhythm instead of grinding out steep, technical terrain lap after lap, and it keeps the format approachable for runners newer to long time-on-feet efforts.

Because you pass the start/finish and your own camp every loop, this is one of the easiest formats to crew yourself. Stage exactly what you need for the next lap or two rather than carrying a full kit, and use the frequent access to check in on your feet, your fueling, and your pace.

Three windows, three different races

The 6 hour window suits a strong trail runner looking for a solid, honest effort without an overnight commitment. The 12 hour window pushes into real ultra territory, likely spanning sunset or sunrise depending on when you start. The full 24 hours turns this gentle loop into a genuine test of sustained pacing, fueling, and sleep management across a full day and night. Pick the window that matches the kind of day (or day and night) you actually want to have.

Free camping makes it a weekend, not just a race

Suttle Lake Trailfest includes free camping at South Shore Campground for the weekend, so runners and crew can set up before race morning and stay through the finish. That low-friction logistics setup, camp right at the venue, loop right past your tent, is a big part of what makes this race feel more like a community weekend than a high-stakes event.

Pacing strategy for a timed lake loop

Pacing a timed race is not about a finish split, it is about picking a loop pace you can hold, with intentional recovery baked in, for your entire chosen window.

Even loops beat a fast start

On a soft, flat 3.6 mile loop the temptation is to bank easy miles fast early on. Resist that for anything beyond the 6 hour window. A grade-adjusted pace target for the modest 110 feet of gain gives you an honest sense of what effort is genuinely repeatable, whether that is 10 loops or 30, rather than a pace that only survives the first two hours.

Know what a full window actually costs you

Use a race-time prediction off your real fitness to sanity-check what holding a given loop pace does to you across 6, 12, or 24 hours. For the longer windows especially, build in planned walk breaks and aid stops from the start rather than waiting until you are forced into them, and set a lap-count goal you can check yourself against as the hours pass.

⏵ Free tools to plan your loops

Fueling strategy for your chosen window

How you fuel Suttle Lake depends entirely on which window you picked. A 6 hour effort fuels like a long trail run; a full 24 hours fuels like a genuine ultra with an overnight stretch.

6 and 12 hours: steady carbs, simple execution

For the shorter windows, aim for roughly 60 to 90 grams of carbohydrate per hour, similar to any multi-hour trail effort. The loop's frequent aid access at the start/finish makes it easy to stick to a simple, repeatable plan (a gel or two plus what you carry) rather than improvising lap to lap.

24 hours: treat it like an overnight ultra

For the full day, lean on real food alongside gels as the hours stack up, since appetite and gut tolerance shift over that long a stretch. Keep sodium in the 300 to 700 mg per liter range, and plan for the October night to cool things down considerably, both in temperature and in what your stomach can handle. Use your camp, right on the loop, to stage warm layers and hot food for the overnight laps.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight and your chosen window 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 kind of sustained time-on-feet a timed race demands. Summit Line reads your real training, builds the durability your chosen window asks for, and rehearses your fueling so the loops become something you execute, not guess at.

Start free →Explore the demo

Suttle Lake Trailfest FAQ

How does the Suttle Lake Trailfest work?

It is a timed race, not a fixed distance. You pick a window, 24 hours, 12 hours, or 6 hours, and run as many laps as you can of a 3.6 mile loop around Suttle Lake before your time runs out. There is no set finish line to cross and no required pace, just accumulated loops within your chosen window. Whoever covers the most distance in their category wins, and everyone else gets to say how many loops they banked.

How hard is the Suttle Lake Trailfest?

It is genuinely mellow by ultra standards, which is the point. The 3.6 mile loop carries only about 110 feet of gain, a soft, flat profile compared to the mountainous races Central Oregon is known for. The difficulty scales entirely with how long you choose to run: the 6 hour option is approachable for a solid trail runner, while the 24 hour option turns a gentle loop into a real test of fueling, pacing, and mental patience over a full day and night.

How much climbing is at Suttle Lake?

Each 3.6 mile loop carries about 110 feet of elevation gain, a soft, mostly flat lakeside profile. That is a fraction of what nearby Central Oregon mountain races like Run The Rock or Three Sisters Skyline demand, which is exactly why Suttle Lake works as a gentler, more approachable format even at the 24 hour distance.

How should I fuel for a timed race like Suttle Lake?

Fueling for a timed event is about your chosen window, not a fixed mileage. For the 6 or 12 hour options, aim for roughly 60 to 90 grams of carbohydrate per hour, similar to any multi-hour trail effort. For the full 24 hours, treat it more like an ultra-distance timed event: steady carbohydrate intake, real food alongside gels, and sodium in the 300 to 700 mg per liter range, adjusted for how the October night cools things down. Build your numbers with the free ultra fueling calculator before race day.

What are the cutoffs at Suttle Lake Trailfest?

There is no per-loop cutoff published for this soft, flat loop. Your race simply ends when your chosen window, 24, 12, or 6 hours, closes, wherever you are on the loop at that moment. That makes Suttle Lake more forgiving than a checkpoint-cutoff race: a slow lap does not eliminate you, it just means fewer total loops by the time your clock runs out.

Is Suttle Lake Trailfest a good first ultra?

Yes, it is one of the more beginner-friendly ultra formats in Central Oregon. The loop is short, soft (about 110 feet of gain per lap), and you pass the start/finish and your own camp every 3.6 miles, so aid, gear changes, and mental breaks are always close by. Free camping at South Shore Campground makes the weekend low-stress too. Start with the 6 hour or 12 hour window if it is your first timed event, and treat your first few loops as a chance to dial in a pace you can actually repeat.

Link this guide

Race directors and clubs: link or embed this guide anywhere. It stays current.

HTML link
<a href="https://runsummitline.com/guides/suttle-lake-trailfest">The Suttle Lake Trailfest course guide</a>
Iframe embed
<iframe src="https://runsummitline.com/embed/race/suttle-lake-trailfest" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Suttle Lake Trailfest course guide by Summit Line"></iframe>

This guide is independent and for planning only. The format, date, start time, and course 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.

The timeline

Get the week-by-week countdown for this race: when to build, when to peak, when to taper.

One email with the timeline, plus training notes for this race. Unsubscribe any time.