Kodiak Ultra Marathons by UTMB Course Guide

The terrain: alpine singletrack, fire road, and the PCT

The footing is a mix of smooth rolling singletrack, fire road, and rockier mountain trail. The race uses Big Bear’s North Shore Trails, the flowing Skyline Trail, and a few real miles of the Pacific Crest Trail through Holcomb Valley. You go from alpine forest under big pines into more open high-desert sections with granite boulders and even Joshua trees down low. Most of it is runnable when you are fresh, and that is exactly the trap. The easy early footing tempts you to bank time, and you pay it back with interest on the climbs.

Exposure is a big deal out here. A lot of the ridge and high-desert-edge sections are wide open to the sun with almost no shade, so the same trail that feels nice at dawn turns into a radiator by mid-day. The 50K climbs the face of Snow Summit early, then hands you the smooth Skyline singletrack along the ridge as the payoff.

The Sugarloaf climb: the crux of the 100 miler

The big one on the 100 mile is the climb up Sugarloaf Mountain, the high point at 9,995 ft. And it sits deep in the back half of the race, so you hit the biggest, highest climb of the day when you are already tired and already at altitude. This is the spot where the 100 miler is most often won or lost. The runners who hammered the early runnable miles show up at Sugarloaf with empty legs and not enough air, and the patient ones just climb right past them.

Treat the first long stretch as setup, not as the race. For the opening quarter the goal is simple: get to the foot of that late climb with your legs, your stomach, and your headlamp plan all still intact. The race really starts when the big climbing does.

Altitude, heat, and night: the conditions tax

Three things stack up on you at Kodiak. First is altitude. Running for hours above 7,000 ft with a near-10,000 ft summit means your pace at a given effort is slower, and your gut and your breathing both work harder, especially if you live at sea level. Second is the day-night swing. An early-October Big Bear day can be warm and dry in the open sun and then drop toward or below freezing at the high points overnight, so on the 100 mile and 100K you get real cold after dark on top of the heat you already dealt with. Third is the dry air, which quietly speeds up dehydration. You sweat and breathe off more fluid than you feel.

None of this is a reason to be scared of the course. But every one of those taxes a plan built for a flat, cool, sea-level race. Your pace, your fuel, and your kit all have to account for it.

Aid stations and cutoffs

Kodiak puts out full aid station charts (imperial and metric) for each distance, with the intermediate cutoff at every station. The overall limits sound generous (36 hours for the 100, 20 for the 100K, 10 for the 50K), but the intermediate cutoffs are what actually end days. And they bite hardest right where the late climbing slows everybody down.

Before race week, pull the official aid station chart for your distance and write down your target arrival time at each station with some cushion. Plan your crew, your drop bags, and your headlamp and warm-layer swaps around the exact stations where you will hit the cold high country in the dark.

Pace the climbs by effort, not by your flat-ground pace

On a course this vertical, your flat road or treadmill pace means nothing. What gets you to the finish is grade-adjusted effort: a controlled hike on the steep stuff, an easy jog on the rolling singletrack, and a lot of patience on the runnable early miles. The biggest pacing mistake at Kodiak is running the easy early terrain too fast and showing up at the Sugarloaf climb with nothing left.

Figure out a realistic effort for each grade before race day, not during the race. Our grade-adjusted pace calculator turns your normal pace into the effort-equivalent pace for the climbs and descents, so you can build a hike-vs-run plan you can actually hold all day.

Predict a finish that accounts for the vert and altitude

A finish-time goal you pulled off a road marathon will be way too optimistic here. With about 15,900 ft of gain on the 100 mile (and 10,240 ft on the 100K), plus the altitude, your moving pace is going to be a lot slower than your flat ultra pace. And the climbs eat time you will not get back on the descents.

Use our race-time calculator to build a vert-aware finish prediction for Kodiak, then check it against the intermediate cutoffs. If your honest splits are bumping up against the cutoffs, that is your sign to start more conservatively, or to put more climbing into your training block right now.

Set the goal off a course-honest equivalent

Not sure what you can do at this distance with this much climbing? Start from a race you have already run. Our race-equivalent calculator turns a recent finish into an equivalent effort at a new distance, so you get an honest baseline before you stack Kodiak’s vert and altitude on top of it. From that baseline, set a goal band, a stretch time and a safe time, instead of one single number. And run the early hours toward the safe end.

Carbs that ramp with the length of your day

Kodiak is long and the high country kills your appetite, so your carb plan has to be both ambitious and easy to get down. As a rule, carbs go up with how long you are out there. Around 60 to 70 g per hour is plenty for the 50K, while the 100K and 100 mile reward a trained gut taking 80 to 90+ g per hour from a glucose-plus-fructose blend. Up at altitude on the Sugarloaf climb, lean on liquids and gels instead of solid food your stomach does not want.

Get a concrete starting point from our ultra fueling calculator. Enter your weight, your goal time, and the Big Bear forecast, and it hands you a carb, sodium, fluid, and caffeine plan per hour you can practice on your long runs.

Hydration and sodium for dry mountain air

The dry Southern California air up at altitude hides how much fluid you are losing. You are sweating in the open sun and breathing off water in the thin air, and you never feel soaked. Pair every bit of fluid with sodium dialed to your own sweat rate (commonly 300 to 700 mg of sodium per liter, biased high in the mid-day heat) so you do not show up at the late climbs cramped and sloshy. Weigh yourself before and after a hot long run in training to find your real sweat rate. Do not guess at it.

Plan for the temperature swing. More fluid and sodium through the warm, exposed mid-day, then a deliberate switch to warm calories and a steadier sip overnight at the cold high points.