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Tahoe Rim Trail Endurance Runs Course Guide
TRTER is a high, dry mountain race in the Carson Range above the east shore of Lake Tahoe. Thin alpine air, a steep climb up Diamond Peak, the dusty Red House Loop, big rim views, and a high-country night on the longer distances. It is a lot. I will walk you through the course across the 100 mile, 100K, 50K, and 23K, then give you pacing and fueling that is built for exactly these conditions, plus free tools to dial in your own numbers.
The course
TRTER runs through the Carson Range of the Sierra Nevada on the Nevada side of Lake Tahoe, stitching together Tahoe Rim Trail singletrack with dirt service roads through the Spooner backcountry of Lake Tahoe Nevada State Park and Toiyabe National Forest. It is a high, dry, alpine course. The 100 mile carries about 18,140 feet of gain, the 100K about 10,750 feet, and the 50K about 6,000 feet, with the high point near Snow Valley Peak at about 9,214 feet. The longer distances loop back on themselves, so you pass the major aid stations more than once.
The climb to the rim sets the tone
From the Carson City start, the course climbs hard toward the rim, gaining roughly 4,200 feet in the first ten miles up toward Snow Valley Peak. That is a big bite of vertical this early, and at altitude. And it is the trap. It feels fine while your legs are fresh, but the air is already thinner than what most runners trained in, so a grade that feels easy is quietly costing you more than it would at home.
The smart move is to climb this opening by effort, power-hiking the steep pitches with purpose and saving your running legs for the runnable rim that comes after. Do not chase a pace number on the first big climb. At 8,000 to 9,000 feet your sea-level pace is just not going to show up.
Diamond Peak and the Red House Loop
The climb everyone remembers is Diamond Peak, a steep grind up the ski runs of about 1,700 feet in under 2 miles to roughly 8,540 feet. It is the steepest sustained climb on the course, and on the 100 mile you do it twice. Power-hike it efficiently, with poles if you train on them. Do not try to run it.
The 100 mile also has the Red House Loop, a roughly three-mile descent down to the low point of the loop and then a dusty, sandy three-mile climb back out on jeep roads. The climb out is loose and slow, the kind of footing that grinds you down late in a race. Know it is coming and respect it on the first pass, and the second pass treats you better.
Altitude, dry heat, and the rim views
The course spends most of its miles between about 7,000 and 9,200 feet, so the altitude is with you the whole way, not just once. The mid-July Sierra sun on the open, exposed sections can get genuinely warm, and the dry alpine air pulls fluid out of you faster than the temperature lets on. For a lot of runners it is the heat and the dehydration, not the climbs, that does the real slowing.
The payoff is the views. Long stretches open up to Lake Tahoe and the Great Basin, the part the race calls a glimpse of heaven. Stay on top of your fluid and sodium through the exposed hours so you can actually enjoy them instead of just surviving them.
Aid stations, the loops, and cutoffs
The aid stations here are well stocked, with Tunnel Creek as the hub that 100 mile runners pass several times as the route loops back on itself, plus stations at Snow Valley Peak, Hobart, Diamond Peak, Waterfall, and the Ash Canyon trailhead near the finish. Drop bags are allowed at the major checkpoints. The aid is some of the best stocked you will run through.
The 100 mile has a 36 hour limit, the 100K a 24 hour limit with a sub-20 hour Western States qualifying standard, and the 50K runs to roughly 20 hours, all with an early firm 3 hour cutoff at Kick Ash and timed cutoffs at Diamond Peak. Build your pacing plan backward from the cutoff chart for your distance, and leave yourself a buffer, because the altitude and the climbs slow everyone down late.
Pacing strategy for TRTER
A high-altitude, climbing-heavy mountain race rewards patience and punishes ego. Pace this one by effort and by grade at elevation, not by the flat-ground numbers from your home training runs.
Pace the climbs by grade and breathing
On a course with this much vert and this much altitude, your moving pace will swing all over the place between the climbs and the runnable rim, and that is fine. Power-hike the steep pitches like Diamond Peak and run the gentler grades. Trying to hold a steady minutes-per-mile number across this terrain is a fast way to cook the early climbs and have nothing left for the second Diamond Peak or the Red House climb out.
Use our free grade-adjusted pace calculator to turn your flat fitness into honest effort targets for the steep TRTER climbs, then add a little margin for altitude. The thin air makes a given grade feel harder than the calculator alone will tell you.
Set a realistic finish goal for all that vert
Because the course stacks so much gain and loss at elevation, a flat-course finish estimate will lie to you and tell you something too fast. Use our vert-aware race time calculator to fold the climbing into your projected finish, then check it against the cutoffs for your distance so you know how much buffer you really have at the key checkpoints.
And if you want to test your goal against a recent result, our race equivalent calculator turns a road or trail race into a realistic TRTER target before you lock in a finish time.
Run the loops smart and respect the night
On the 100 mile and 100K the course loops back through the same aid stations, so you get to scout the terrain on the first pass and run it with more confidence on the second. The climbs are not what get you, the descents are. Hold back on the early downhills, run them light and controlled instead of letting gravity hammer your quads, and your back half will be a different race.
Then plan for the high-country night on the longer distances. Once the sun is down at this elevation the temperature can drop fast, so carry layers, keep eating through the low hours, and keep moving with some margin against the cutoffs so the dark and the altitude do not put you behind the clock.
Fueling strategy for TRTER
A high, dry, all-day-and-night effort makes fueling and hydration matter as much as fitness. Altitude kills your appetite and dry air steals your fluid, so plan for both on purpose.
Carbs: stay disciplined when the appetite fades
For an effort this long, go for roughly 60 to 90 grams of carbohydrate per hour, leaning toward 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 practice your exact hourly carb number on long training runs so it is routine on race day, not an experiment.
Altitude is the catch. The higher you go, the more your appetite drops, right when the work is still hard. That is one more reason to fuel on a schedule instead of by feel, and to keep taking in calories through the long climbs and the night when your stomach would rather quit on you.
Sodium and fluid: built for the dry, thin air
The dry Sierra air and the exposed, sunny climbs run up both your sweat and the water you lose just breathing, so push your sodium toward 500 to 700 mg per liter of fluid and carry enough to cover the longer gaps between aid stations. Cramping, a sloshy stomach, that wrung-out late-race feeling: usually those are fluid and sodium problems, not fitness problems. And at altitude they show up faster.
Dial in a personalized plan with our free ultra fueling calculator. Put in your weight, your goal time, and the conditions you expect, and it gives you a carb, sodium, fluid, and caffeine number per hour built for the TRTER duration and altitude. Then go test it in training.
This guide is for planning and training purposes and reflects publicly available information about the Tahoe Rim Trail Endurance Runs. Race details, including the date, course, aid stations, cutoffs, and qualifier status, can change year to year. Always confirm the current specifics on the official TRTER race website before you train or travel.