⏵ Course guide · Free
The Big A 50K is a volunteer-run trail race on Mount Agamenticus in York, Maine, three loops of about 10.35 miles that climb the Big A summit, Second Hill, and Third Hill each time around, for 5,787 feet of total climbing. Entry is not a commercial race fee. It is a minimum $20 donation to the Mount Agamenticus Conservation Program, and that is part of what this race is, not a footnote. I will walk you through the course, then give you a pacing and fueling plan built for repeated climbing, with free tools to dial in your own numbers.
These facts come from the official Mount Agamenticus Conservation Program race listing and RunSignUp. Check the current date and race-day details before you commit. Race logistics change year to year.
The 50K is three loops of about 10.35 miles each, and every loop climbs the Big A summit along with Second Hill and Third Hill, for 5,787 feet of total elevation gain across the full race. The terrain is mostly singletrack with some dirt road and ATV trail mixed in, and the climbing repeats rather than building to a single crux.
You climb Big A, Second Hill, and Third Hill on the very first loop, so there is no easing into this race. About 1,930 feet of gain shows up in the first 10.35 miles, and that sets the tone for the two loops still ahead. This is the heart of the race.
Climb the first loop with real patience. Every summit you hit here you hit two more times, so there is nothing to gain by rushing it and a lot to lose in your legs for laps two and three.
The second loop is where the race stops being about any one climb and starts being about your ability to keep doing the same climbs with less in the tank. Big A, Second Hill, Third Hill, again. The terrain has not changed. Your legs have.
Runners who front-load too much effort into loop one often find loop two is where it catches up with them. Keep your climbing effort consistent lap to lap rather than letting the first loop set an unsustainable bar.
By the third loop you have climbed each of the three summits twice already, and you do it again before you are done. The recommended 10-hour finish is guidance, not a strict cutoff, which fits a volunteer-run event: the emphasis is on finishing well, not racing a clock imposed from outside.
If a loop is not going your way, informal early exits exist at the loop boundaries, roughly every 10 to 13 miles. That flexibility is part of what a volunteer, community race like this offers that a tightly timed commercial event usually does not.
With 5,787 feet of gain split across three identical loops, this is a race you pace by managing repeated effort, not by hitting a single big climb once and coasting the rest of the way.
Your flat-ground pace does not translate to climbing Big A, Second Hill, and Third Hill three separate times. What matters is grade-adjusted effort you can repeat, not a number you can only hold once. Use a grade-adjusted pace to turn your real fitness into honest climbing targets for each loop, so the third summit push does not fall apart just because the first two felt fine.
It is easy to look at one 10.35-mile loop and misjudge the full day, because the climbing compounds across three trips up the same hills. A vert-aware finish prediction that accounts for the complete 5,787 feet of gain gives you a realistic window against the 10-hour recommended finish, instead of a guess based on how loop one felt.
⏵ Free tools to pace this course
With three summit climbs per loop and 5,787 feet of total gain, carbohydrate and sodium matter just as much as fitness across a 10-hour effort.
Aim for roughly 60 to 90 grams of carbohydrate per hour, pushing toward the higher end if your gut is trained for it. Because you pass back through the start/finish area after every loop, use those crossings to check your intake against your plan rather than realizing three hours in that you have fallen behind. The climbing on each loop burns through glycogen fast, so do not wait until you feel low to start eating more.
Early May in York, Maine can run anywhere from cool and damp to warm and sunny, so keep sodium in the 300 to 700 milligram per liter range and adjust based on the actual forecast and your own sweat rate. Carry enough fluid to cover each climbing loop, since the repeated summit efforts push your fluid needs higher than a flatter 50K would.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and this course's repeated climbing with the free ultra fueling calculator. Browse the rest of the free running tools at the tools hub.
⏵ Free calculators for this race
Run your Big A numbers with our free, no-signup tools, then let Summit Line tie all of it to your real fitness and this exact course.
⏵ Train for it with Summit Line
Get a race-day plan built around YOUR fitness, this exact Big A course profile, and your projected splits. Summit Line reads your real training, builds a plan for the repeated summit climbing, and rehearses your fueling so race day is something you execute, not guess at.
It is a genuinely tough 50K built around repeated climbing, not distance alone. The course is three loops of about 10.35 miles each, and each loop climbs Big A summit along with Second Hill and Third Hill, adding up to 5,787 feet of total elevation gain, officially confirmed. That is a lot of vert stacked into a 50K, and repeating the same climbs three times means your legs feel every one of them. The 10-hour recommended finish is guidance, not a hard cutoff, which fits the race's whole character: this is a volunteer-run event on Mount Agamenticus, not a commercial production chasing a tight schedule.
The official total is 5,787 feet of elevation gain across the full 50K, spread over three loops of about 10.35 miles each. Every loop climbs the Big A summit itself along with Second Hill and Third Hill, so the climbing is repeated, not a one-time crux. That is roughly 1,930 feet of gain per loop, which is significant for New England terrain and means the course never really lets you settle into flat running for long.
With 5,787 feet of climbing spread across three loops, plan your fueling around a multi-hour effort with real vert, not a flat 50K. Most runners do well on roughly 60 to 90 grams of carbohydrate per hour, leaning toward the higher end if your gut is trained for it, with sodium scaled to early-May Maine conditions, generally in the 300 to 700 milligram per liter range depending on the weather. Since you cross the start/finish area after every loop, use those passes to check your numbers instead of guessing across the full 50K. Dial in your own plan with the free ultra fueling calculator.
There is no strict, hard cutoff at the Big A 50K. The race gives a 10-hour recommended finish time as guidance rather than a drop-dead line, which reflects the volunteer, donation-based nature of the event. That said, treat 10 hours as your real planning target given the 5,787 feet of repeated climbing, and do not assume open-ended time just because it is not framed as a strict cutoff.
The course is mostly singletrack with some dirt road and ATV trail mixed in, and it repeats climbs of the Big A summit, Second Hill, and Third Hill across all three loops. Expect rocks and roots typical of Maine trail, plus the physical toll of climbing the same hills three separate times rather than once. Runners looking for an early exit can drop out at loop boundaries, roughly every 10 to 13 miles, an informal option that fits the race's low-key, supportive character.
Because it is not a commercial race. The Big A 50K is entirely volunteer-run, and entry is a minimum $20 donation to the Mount Agamenticus Conservation Program rather than a standard registration fee. That donation-based model is central to what this race is: a community and conservation event on land that a nonprofit works to protect, put on by people volunteering their time, not a for-profit production. If you register, understand you are supporting the trails you are about to run on, not just buying a bib.
This guide is independent and for planning only. The course details, dates, and race-day logistics 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.