⏵ Course guide · Upper Peninsula self-supported ultra
Marji Gesick runs its 50 and 100 mile foot races through rugged, technical singletrack across Marquette County in Michigan's Upper Peninsula, fully self-supported: no aid stations, no course marking, GPS mandatory. The race is best known for its brutal mountain bike event and a famously low finish rate. I will walk you through the format and terrain first, then give you a pacing and fueling plan built for total self-sufficiency, plus free tools to dial in your own numbers.
These facts come from the official 906adventureteam.com event page. Check the current year details, cutoffs, and rules before you commit. Race logistics change year to year.
Marji Gesick's defining feature is not a climb or a landmark, it is the total absence of race-operated support. Everything you need, you carry or stage yourself.
The organizers do not run aid stations of any kind, and they do not mark the course. GPS is mandatory, because it is the one thing that still works when weather takes out any informal markers. The race's own self-supported statement is blunt: "We do not hold your hand." Study your GPX file before race day, not during it.
MG100RUN starts Friday at 8:00 AM from the Forestville Trailhead. MG50RUN starts Saturday at 7:00 AM from the Lower Harbor Ore Dock in Marquette. Both, along with every other Marji Gesick event, close together on Sunday morning at 8:30 AM ET, so the two distances share a single closing horn even though they start on different days.
Drop bags go to Jackson Park in Negaunee, and race staff move your bag there for you if you hand it off at the start line. For the 100-mile run, expect to pass it near miles 65 and 85. For the 50-mile run, expect it near miles 15 and 35. Between those touches, you are on your own, so pack accordingly and do not assume help will be available from anyone but yourself.
With no aid stations to structure your day around, pacing at Marji Gesick is really about managing your own resupply intervals and the 28-hour belt-buckle clock for the 100-mile run.
Without official aid stations, your two Jackson Park touches are your only fixed checkpoints. A grade-adjusted pace target for rugged, technical singletrack gives you an honest estimate of how long each stretch between drop bags will actually take, which matters more here than it does on a fully supported course, since running out of supplies mid-stretch has real consequences.
The 100-mile run's belt-buckle cutoff is 28 hours, but the hard close for every Marji Gesick event is Sunday 8:30 AM ET. A vert-aware finish prediction, built conservatively for technical, self-navigated terrain, helps you decide early whether you are racing for the buckle or simply racing to finish, since the effort required for each is different.
⏵ Free tools to pace this course
With zero race-operated aid, every calorie and every ounce of sodium on course comes from what you carried or staged yourself.
Aim for roughly 60 to 90 grams of carbohydrate per hour, then pack for the full distance between your Jackson Park touches, plus real margin for a slower-than-planned pace. Running short between drop bags here is not an inconvenience, it can end your race, so err heavy rather than light.
A baseline of 300 to 700 mg of sodium per liter is a reasonable starting point, but you also need a real water plan since the race does not operate water stops. Know your route's natural water sources if you plan to filter, and never assume local trail users or informal aid will be there, the organizers are explicit that any help from others is outside their control and not something to plan around.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a fully self-supported day on Upper Peninsula singletrack 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 race-day plan built around YOUR fitness, this course's self-supported demands, and your projected splits between drop bags. Summit Line reads your real training, builds a plan for technical, unsupported terrain, and rehearses your fueling so race day is something you execute, not guess at.
Marji Gesick has built a reputation as one of the hardest single-day endurance events in the country, and the run divisions inherit that reputation directly. The event is fully self-supported: no race-operated aid stations, no course marking, and GPS is mandatory because you are entirely on your own to navigate rugged Upper Peninsula singletrack. The race's own results page is blunt about it, calling itself a long list of DNFs, and cites a 70% DNF rate in 2017. This is not a race to attempt without serious self-sufficiency experience.
The organizers do not publish an official elevation figure for the run divisions. What they do say, in the event's own history, is that the route was designed to run "uphill from start to finish, and hard as hell." Expect rugged, technical Upper Peninsula singletrack with sustained climbing rather than one defining summit, and do not trust any specific vert number you see quoted elsewhere unless it comes from the official race page.
With no race-operated aid stations of any kind, fueling here is entirely on you. Plan to carry everything you need between your two Jackson Park drop-bag touches (roughly miles 15 and 35 for the 50-mile run, miles 65 and 85 for the 100-mile run). Aim for roughly 60 to 90 grams of carbohydrate per hour and sodium in the 300 to 700 mg per liter range as a baseline, then build in real margin, since a missed drop bag or slower-than-planned pace means going without resupply for a long stretch. Build your numbers with the free ultra fueling calculator before race day, then pack accordingly.
The 100-mile run has a 28-hour belt-buckle cutoff. All Marji Gesick events, across every distance and discipline, close on Sunday morning at 8:30 AM ET. Given the MG100RUN starts Friday at 8:00 AM, that is a maximum window a bit over 48 hours, but the buckle cutoff of 28 hours is the number serious finishers are actually racing against.
Expect rugged, technical singletrack across Marquette County's Upper Peninsula trail network, connecting trailheads including Forestville, the Lower Harbor Ore Dock, and Jackson Park in Negaunee. The course is not marked by the race, and no aid or support is provided beyond what you and your crew arrange, so route-finding and self-sufficiency are as much a part of the challenge as the terrain itself.
No. The event's own self-supported statement is direct about this: no aid stations, no course marking, GPS required, and real consequences for being unprepared. This is built for runners who already have ultra experience and are comfortable navigating and fueling themselves for a full day or more with no safety net beyond two drop-bag touches. If you are newer to the distance, look for a fully supported 50 or 100 first and treat Marji Gesick as a race to build toward.
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<a href="https://runsummitline.com/guides/marji-gesick-run">The Marji Gesick Run course guide</a><iframe src="https://runsummitline.com/embed/race/marji-gesick-run" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Marji Gesick Run course guide by Summit Line"></iframe>This guide is independent and for planning only. The course details, dates, cutoffs, and 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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