⏵ Course guide · De Soto National Forest, Mississippi
The Mississippi Trail 50 mixes a 12.6 mile big loop and a 6.1 mile small loop through gently rolling pine forest on the Longleaf Horse Trail south of Laurel, now in its 30th year with 100M, 50M, 50K, and 20K options. I will walk you through the loop combinations and aid setup first, then give you a pacing and fueling plan built for repeated Mississippi pine-forest miles, plus free tools to dial in your own numbers.
These facts come from the official UltraSignup registration page and ms50.com. Check the current year details and cutoffs before you commit; race logistics can change year to year.
A 12.6 mile "big loop" and a 6.1 mile "small loop" combine in different counts for each distance: 7 big plus 2 small for the 100 Miler, 3 big plus 2 small for the 50 Miler, 2 big plus 1 small for the 50K, and 1 big loop for the 20K.
Every big loop passes the full aid station at mile 6.2, nicknamed the MUTS station after the Mississippi Ultra & Trail Series, and a water-only out-and-back stop at mile 8.7. The longest stretch without aid on the big loop is 6.2 miles, so plan your carry around that gap rather than the full loop distance.
Expect gently rolling terrain through pine forest, mostly singletrack with some doubletrack logging roads mixed in. This is not a technical or high-vert course, which is part of why it works well as a first 50K or 50 Mile for runners building toward bigger mountain ultras.
The 100 Miler is the distance where pacing really matters: five staged interval cutoffs mean you cannot bank one fast stretch and coast, you need to hit each checkpoint on schedule.
With cutoffs at 50.4 miles (15 hours), 63.0 miles (18h45), 75.6 miles (22h29), 88.2 miles (26h14), and 94.6 miles (28h08), the 100 Miler rewards even, sustainable pacing across all 7 big loops and 2 small loops rather than a fast start. A race-time calculator can help you build a realistic per-loop schedule against these specific checkpoints.
⏵ Free tools to pace this course
Early March in south Mississippi is usually mild, but 100 Mile runners will be on course through at least one full night, so plan fueling for real temperature swings.
Aim for roughly 60 to 90 grams of carbohydrate per hour, and keep sodium in the 300 to 700 mg per liter range depending on conditions. The full MUTS station at mile 6.2 is your best resupply point on the big loop; the mile-8.7 water-only stop means you should carry your own calories through that stretch rather than expecting food there.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight and your goal time 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 mixed big-loop and small-loop Mississippi course, and your projected splits against every interval cutoff. Summit Line reads your real training, builds a plan for gently rolling pine-forest miles, and rehearses your fueling so race day is something you execute, not guess at.
The race combines a 12.6 mile "big loop" and a 6.1 mile "small loop" through gently rolling pine forest on the Longleaf Horse Trail in De Soto National Forest, mostly singletrack with some doubletrack logging roads. It is a genuinely runnable course without major elevation or technical obstacles, which is part of why organizers pitch it as a good place to try a first 50K or 50 Mile. Thirty years of continuous running and a well-established local aid crew (the famous MUTS station) back that reputation up.
Every distance mixes big (12.6 mile) and small (6.1 mile) loops: the 100 Miler runs 7 big loops plus 2 small loops, the 50 Miler runs 3 big loops plus 2 small loops, the 50K runs 2 big loops plus 1 small loop, and the 20K runs a single big loop. Knowing which loop you are on, and how many of each you have left, matters for pacing since the aid station spacing differs slightly between the two loop types.
Yes, if you are a Saturday starter (50 Mile, 50K, or 20K runner). You may switch to a shorter distance after completing one or more loops, and you will still be counted as a finisher of the distance you actually complete, just not eligible for a trophy. Notify race officials at the timing tent when you drop. The 100 Miler is different: it is all-or-nothing, you either finish 100 miles by the Saturday 6 PM cutoff or you get a DNF, with no dropping down to a shorter distance.
Early March in south Mississippi is usually mild, good conditions for steady fueling, though conditions can vary. Aim for roughly 60 to 90 grams of carbohydrate per hour, and keep sodium in the 300 to 700 mg per liter range depending on the day. The mile-6.2 station on the big loop, nicknamed the MUTS station, is the race's signature full-service stop, and the longest gap to any aid on the big loop is 6.2 miles, so plan your carry accordingly. Build your numbers with the free ultra fueling calculator before race day.
The 50 Miler, 50K, and 20K all share a 12-hour time limit. The 100 Miler runs on a 30-hour all-or-nothing clock from its Friday noon start to a Saturday 6 PM cutoff, with staged interval cutoffs along the way: 50.4 miles by 15 hours, 63.0 miles by 18h45, 75.6 miles by 22h29, 88.2 miles by 26h14, and 94.6 miles by 28h08. Missing an interval cutoff on the 100 Miler ends your race; there is no dropping to a shorter finish.
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<a href="https://runsummitline.com/guides/mississippi-trail-50">The Mississippi Trail 50 course guide</a><iframe src="https://runsummitline.com/embed/race/mississippi-trail-50" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Mississippi Trail 50 course guide by Summit Line"></iframe>This guide is independent and for planning only. The course details, dates, cutoffs, and aid stations 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.