⏵ Course guide · Mammoth Cave National Park, Kentucky
The Mammoth Cave 50K/25K runs out-and-back on the crushed gravel Bike & Hike Trail inside Mammoth Cave National Park, starting at Bell’s Tavern Pavilion in Park City, Kentucky, a cupless race capped at 150 runners that historically sells out fast. I will walk you through the course and format first, then give you a pacing and fueling plan built around the 8-hour cutoff, with free calculators along the way to dial in your own numbers.
These facts come from the official RunSignup event page. Exact elevation gain and entry fee were not published there at the time of writing, so confirm those before you register.
The race runs out-and-back on the Bike & Hike Trail’s crushed gravel surface inside Mammoth Cave National Park, with the race itself flagging "challenging ascents/descents" along the way.
Because this is an out-and-back course, you will see faster runners on their return trip while you are still heading out, a built-in pacing check. Use that as information, not pressure: your turnaround point marks the halfway commitment for whichever distance you chose.
This is a cupless race. Aid stations offer water, sports drink, and snacks, but you need a collapsible cup, bottles, or a hydration pack to actually use them. Show up without one and you cannot drink at the aid stations as intended, so pack this the same way you would pack shoes.
Both distances share the same 8-hour window from a 7:00 AM Central start, with a firm 3 PM end. Build your pacing plan around that limit, not just around finishing.
With the race stating plainly it "will end by 3 pm," treat 8 hours as a hard ceiling, not a target. Aim to reach the halfway turnaround comfortably ahead of the pace that 8 hours would require, so the challenging ascents and descents on the way back do not put the cutoff in doubt.
⏵ Free tools to plan your effort
Since aid stations offer only water, sports drink, and snacks, not a full aid-station buffet, plan to carry the bulk of your own nutrition for the 50K.
Aim for roughly 45 to 65 grams of carbohydrate per hour on the move for the 50K, with sodium in the 300 to 500 mg per liter range as a starting point, adjusted for a late-October Kentucky day that can run cool. Bring your own collapsible cup or hydration pack from the start line, since the race will not provide one, and treat the on-course sports drink and snacks as a supplement to your own plan rather than the whole plan.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a late-October Kentucky day 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 training plan built around YOUR fitness and the 8-hour cutoff the Mammoth Cave 50K asks you to beat. Summit Line reads your real training, builds the pacing discipline and durability this out-and-back demands, and rehearses your fueling so race day is something you execute, not guess at.
It means the race does not provide disposable cups at aid stations. You need to bring your own collapsible cup, bottles, or a hydration pack to receive water and sports drink from the aid stations, which offer "water, sports drink, and yummy snacks" per the official page. Show up without one and you will not be able to use the aid station fluids as intended.
The course runs out-and-back on the Bike & Hike Trail's crushed gravel surface inside Mammoth Cave National Park, with the race itself noting "challenging ascents/descents." The 8-hour cutoff for the 50K is a real constraint worth respecting, especially with a firm 3 PM end time that applies race-wide.
Both distances share an 8-hour cutoff from the 7:00 AM Central start, meaning the race ends by 3 PM Central. That is a firm limit for the 50K in particular, so build your pacing plan with real margin rather than banking on exactly making it.
Yes, registration is capped at 150 runners for the 6th running, and the official page states plainly that the event sells out quickly. If you want a spot, register as soon as the current year opens rather than waiting.
The crushed gravel Bike & Hike Trail surface is more forgiving underfoot than rocky Kentucky singletrack, which makes this a reasonable first-50K choice if you want a genuine trail setting without highly technical footing. The 8-hour cutoff and the cupless, bring-your-own-cup format are both things to plan for ahead of time as a first-timer.
Registration is through RunSignup at the official event page, capped at 150 total runners. The page offers a "contact the race director" form rather than a published email, so use that form for any questions before you sign up.
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<a href="https://runsummitline.com/guides/mammoth-cave-50k-25k">The Mammoth Cave 50K/25K course guide</a><iframe src="https://runsummitline.com/embed/race/mammoth-cave-50k-25k" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Mammoth Cave 50K/25K course guide by Summit Line"></iframe>This guide is independent and for planning only. Course, date, and logistics come from public sources and can change year to year, so confirm the current specifics with the race before you register or run. The fueling and pacing advice is general and not medical advice.
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