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⏵ Course guide · Alaska's winter classic

Iditarod Trail Invitational Course Guide

The Iditarod Trail Invitational sends its field down Alaska's historic Iditarod Trail on foot, bike, or ski, from Knik Lake toward McGrath (ITI 350) or all the way to Nome (ITI 1000), on an unmarked route through remote winter wilderness. This is a different kind of race than a summer trail ultra: I will walk you through the checkpoints and supply-drop structure first, then give you a strategy built for a multi-day winter effort, plus free tools to dial in your own numbers.

⏵ At a glance

Iditarod Trail Invitational quick facts

Date
February 28, 2027, 2:00 PM start
Location
Knik Lake, Alaska, near Anchorage
Distances
ITI 150 (to Rainy Pass Lodge), ITI 350 (to McGrath), ITI 1000 (to Nome), on foot, bike, or ski
Route
2027 runs the southern route (odd years alternate with the northern route); the route is not marked
Checkpoints
Seven checkpoints with food and minimal lodging, from Butterfly Lake (mile 25) to McGrath (mile 350)
Supply drops
Two for ITI 350 (Finger Lake mi 125, Rohn mi 200); a third for ITI 1000 (Iditarod, mile 473)
Organizer
Intrepid Path (Palmer, AK)
Contact
info@iditarodtrailinvitational.com

These facts come from the official race site, itialaska.com. Check the current year details, route, and checkpoint rules before you commit. Race logistics can change year to year, and the northern and southern routes alternate.

The route: Knik Lake to McGrath, or all the way to Nome

The ITI follows the historic Iditarod Trail from its trailhead at Knik Lake near Anchorage. ITI 350 competitors finish in the remote interior village of McGrath. ITI 1000 competitors continue past McGrath toward the Bering Sea before the trail's conclusion in Nome. After the village of Ophir, the trail diverges into northern and southern routes before rejoining in Kaltag, alternating by year; 2027 runs the southern route.

Seven checkpoints, spaced from 25 to over 100 miles apart

Checkpoint 1, Butterfly Lake, sits at mile 25 with snacks and hot and cold water, and welcomes community visitors to support athletes. Checkpoint 2, Hooligan's Retreat, is at mile 75, where racers pay for meals and lodging if desired. Checkpoint 3, Finger Lake (mile 125), and Checkpoint 4, Puntilla Lake (mile 150), both provide meals and tent lodging, with upgraded options for sale at Rainy Pass Lodge near Puntilla. Checkpoint 5, Rohn, sits at mile 200 with meals and tent lodging. Checkpoint 6, Nikolai, is at mile 300, and Checkpoint 7, McGrath, closes out the ITI 350 at mile 350 with meals, lodging, and hot and cold water. Athletes must sign in and out at every checkpoint.

The route is not marked

This is the single most important fact about the ITI: the official site states plainly that the route is not marked. GPS coordinates for each checkpoint are provided in the Athlete's Guide, but navigating the terrain between them, often in whiteout conditions, blowing snow, and Arctic temperatures, is on the competitor. The race's own guidance is unambiguous: anyone not comfortable navigating in harsh winter conditions over potentially dangerous terrain should not participate.

Supply drops: consumables only, weight capped

ITI 350 competitors get two supply drops, one at Finger Lake (mile 125) and one at Rohn (mile 200), each capped at 5 lb. ITI 1000 competitors get a third drop at Iditarod, mile 473, capped at 10 lb, where liquid fuel is also provided. Drop bags may only contain consumable items such as food, batteries, and hand warmers. All survival gear must be carried by competitors from the start, not shipped ahead.

Strategy for a multi-day winter effort

Pacing an unmarked, human-powered winter race is a different problem than pacing a summer trail ultra. Navigation, cold management, and sleep strategy matter as much as raw fitness.

Checkpoint-to-checkpoint, not mile-to-mile

With checkpoints spaced anywhere from 25 to over 100 miles apart, plan your effort in checkpoint segments rather than fixed daily mileage. Wind, blowing and drifting snow, and water crossings can slow any given segment far more than distance alone predicts, so build slack into your checkpoint arrival estimates rather than locking to a single pace.

A vert- and terrain-aware finish estimate still helps

Even on a winter, human-powered course, a finish prediction built from your actual segment splits beats a flat-ground guess imported from a summer race. Recalculate after each checkpoint as conditions and your own fatigue become clearer, and treat any projection as a moving target given how much weather can shift the trail underfoot.

⏵ Free tools to plan this effort

Fueling and gear strategy for the cold

Calorie needs go up sharply in Arctic temperatures, and every drop bag you plan has to fit inside strict weight limits, so fueling here is as much a logistics problem as a nutrition one.

Plan calories around checkpoint gaps, not a flat hourly rate

Between well-stocked checkpoints like Finger Lake and Puntilla Lake, you can lean on provided meals and tent lodging. On longer, more remote stretches, especially the 100-plus mile push from Nikolai to McGrath, plan denser calories per pound in your carried supplies. Use the free ultra fueling calculator to establish a baseline per-hour target, then adjust upward for cold-weather energy demands.

Drop bags: consumables only, and every ounce counts

With Finger Lake and Rohn capped at 5 lb and Iditarod capped at 10 lb for ITI 1000 racers, prioritize calorie-dense, cold-tolerant food and critical consumables like batteries and hand warmers over bulk. Since survival gear must be carried from the start rather than dropped ahead, your fueling plan has to coexist with the weight of everything else you are hauling.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine baseline built for your weight and goal effort with the free ultra fueling calculator, then adjust it for the cold. Browse the rest of the free running tools at the tools hub.

⏵ Train for it with Summit Line

Get a build built around YOUR fitness heading into a multi-day, human-powered event. Summit Line reads your real training, builds a plan for sustained effort and cumulative fatigue, and rehearses your fueling so race day is something you execute, not guess at.

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Iditarod Trail Invitational FAQ

How hard is the Iditarod Trail Invitational?

The race describes itself, in its own words, as "one of the most challenging experiences on the planet," and the details back that up: competitors travel on foot, bike, or ski down an unmarked winter trail through remote Alaskan wilderness, self-sufficient between seven checkpoints spaced roughly 25 to 100-plus miles apart. The official site is direct about who should attempt it: anyone not comfortable navigating harsh winter conditions in dangerous, remote terrain should not participate.

What is the difference between the ITI 150, 350, and 1000?

The ITI 150 finishes at Rainy Pass Lodge and is described as an introduction to the demands of Alaska's backcountry, useful for runners aiming to eventually qualify for the ITI 350. The ITI 350 follows the historic Iditarod Trail to McGrath. The ITI 1000, the event's full distance, continues past McGrath to the Bering Sea coast and finishes under the burled arch in Nome. All three divisions travel by the same human-powered means: on foot, by bike, or on skis.

How should I fuel for the Iditarod Trail Invitational?

This is a multi-day winter event on an unmarked trail, so fueling strategy has to account for both calorie needs and cold-weather logistics, not just carbohydrate grams per hour. ITI 350 competitors get two supply drops (Finger Lake at mile 125, capped at 5 lb, and Rohn at mile 200, also capped at 5 lb), and ITI 1000 competitors get a third at Iditarod, mile 473, capped at 10 lb, with liquid fuel provided there. Drop bags may only contain consumables: food, batteries, hand warmers, and similar items. All survival gear must be carried by competitors from the start. Build your per-hour carbohydrate targets with the free ultra fueling calculator, then plan your drop-bag contents around the specific mileage gaps between checkpoints.

What are the checkpoints on the Iditarod Trail Invitational?

Seven checkpoints support the route: Butterfly Lake at mile 25 (snacks, hot and cold water), Hooligan's Retreat at mile 75 (meals and lodging available for purchase), Finger Lake at mile 125 (meals and tent lodging provided), Puntilla Lake at mile 150 (meals and lodging provided, with upgraded options for sale at Rainy Pass Lodge), Rohn at mile 200 (meals and tent lodging provided), Nikolai at mile 300 (meals and lodging provided), and McGrath at mile 350 (meals and lodging provided, plus hot and cold water). Athletes must sign in and out at every checkpoint even though the route between them is generally unmarked.

Is the route marked on the Iditarod Trail Invitational?

No. The official race site states this directly and in capital letters: the route is not marked. GPS coordinates for each checkpoint are provided in the Athlete's Guide sent before the race, but navigating between them in harsh winter conditions is the competitor's responsibility. Anyone not comfortable with backcountry winter navigation is told plainly not to participate.

How do I get to and from the Iditarod Trail Invitational?

Pre-race, buses and cargo vans transport athletes and gear from the host hotel, the Hyatt Place Anchorage-Midtown, to the starting line at Knik Lake. Return transport differs by division: ITI 150 finishers get flights included in their entry fee, arranged at Rainy Pass Lodge; ITI 350 finishers arrange and pay for their own return from McGrath; and ITI 1000 finishers arrange their own return flights with Alaska Airlines from Nome.

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This guide is independent and for planning only. The course details, dates, checkpoints, and supply-drop rules 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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