⏵ Course guide · San Diego sunset ultra
Mission Trails Twilight Runs climbs North and South Fortuna Mountains inside Mission Trails Regional Park, starting in the afternoon and running through sunset into a headlamp finish. The 50K stacks up about 7,200 feet of gain and the 25K about 3,600, on a field strictly capped at 300 runners. I will walk you through the schedule and cutoffs first, then give you a pacing and fueling plan built for a race that changes conditions on you mid-effort. There are free calculators along the way to dial in your own numbers.
These facts come from the official Endurance Race Series event page. Check the current year details, cutoffs, and aid stations before you commit. Race logistics change year to year.
Every distance starts and finishes at the East Fortuna Staging area off Hwy 52 and Mast Blvd, climbing North and South Fortuna Mountains inside Mission Trails Regional Park. The staggered, mid-to-late-afternoon start times mean every field crosses from daylight into darkness somewhere on course.
The 50K climbs about 7,200 feet and the 25K about 3,600, both stacked onto North and South Fortuna Mountains rather than spread across a wide backcountry route. That concentration means the climbing comes in sustained, exposed pitches, and the payoff is sunset views from the summits before the course sends you back down into the dark.
The 50K starts at 2:00 PM, the 5K at 2:30 PM, and the 25K at 5:00 PM, and the course does not close until midnight. That means most 50K and 25K finishers will run a meaningful stretch of their race after dark, on the same technical Fortuna Mountain trails they climbed in daylight. Carry a reliable headlamp with backup batteries or a spare light, and if you have never run this specific park at night, treat your daylight miles as a chance to memorize the trail for when the light goes.
The schedule is not just a finish deadline. At 7:00 PM the course closes to anyone who has not started their second loop, the Gate 6 aid station cuts off at 8:00 PM and again at 11:00 PM, and the Clairemont Mesa aid station cuts off at 9:00 PM. Those checkpoints matter more day to day than the midnight course close, since falling behind any one of them puts real pressure on what follows. With the field strictly capped at 300 runners, expect a small, well-supported race rather than a crowded one.
With a 7:00 PM checkpoint tied to your second loop, this is a course where you want to know your split target before the gun goes off, not figure it out somewhere on the mountain after dark.
A grade-adjusted pace target for the Fortuna Mountain climbs gives you an honest number for effort you can hold in daylight and repeat once your headlamp is on and your depth perception is worse. Runners who blow up on courses like this almost always ran the exposed, sun-baked early miles too hard and paid for it once night running slowed their natural pace.
The 7:00 PM second-loop cutoff and the Gate 6 and Clairemont Mesa aid station cutoffs are your real pacing checkpoints, not just the midnight course close. Build a finish projection and check it against those specific checkpoints early, while you still have daylight and room to adjust effort.
⏵ Free tools to pace this course
Starting between 2 and 5 PM means you fuel through the hottest part of the San Diego day before the temperature drops after dark. Plan for both conditions in one race.
Aim for roughly 60 to 90 grams of carbohydrate per hour, using the Gate 6 and Clairemont Mesa aid stations as real checkpoints to reset your intake. Because the race spans a hot afternoon and a cool night, your appetite and thirst will shift over the course of the day, so lean on a written per-hour plan rather than eating and drinking by feel alone.
Keep sodium in the 300 to 700 mg per liter range, leaning toward the higher end during the exposed, sun-baked climbing in the first hours before sunset. Once the temperature drops after dark, you can typically ease off the top end of that range, but keep drinking on schedule since fatigue and lower visibility both make it easy to under-fuel late in a night race.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a race that runs from a hot San Diego afternoon into a cool night 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 exact Fortuna Mountain climbing profile, and your projected splits. Summit Line reads your real training, builds a plan for heavy vert and night running, and rehearses your fueling so race day is something you execute, not guess at.
It is a real climb wrapped in an unusual format. The 50K stacks up about 7,200 feet of gain and the 25K about 3,600 feet, both climbing North and South Fortuna Mountains inside Mission Trails Regional Park. What sets this race apart is not just the vert, it is the clock: a mid-afternoon start means you run into sunset and finish, if you use much of your window, deep into the night on a headlamp. The field is strictly capped at 300 runners, and the event bills itself as the return of racing to a park that had not hosted one in over a decade.
The 50K climbs about 7,200 feet and the 25K about 3,600 feet, both over the North and South Fortuna Mountains inside Mission Trails Regional Park. That works out to well over 200 feet of climbing per mile on both distances, steep for San Diego's trail systems, and it comes with sunset views from the summits before the course drops you back into the dark for the second half of your race.
With a start between 2 and 5 PM depending on your distance and a course that can run past midnight, you are fueling through an afternoon, an evening, and potentially a stretch of full darkness. Aim for roughly 60 to 90 grams of carbohydrate per hour, and keep sodium in the 300 to 700 mg per liter range, leaning higher through the exposed, sun-baked early miles before the temperature drops after dark. The Gate 6 and Clairemont Mesa aid stations give you real checkpoints to reset your intake, but with a race this spread across changing conditions, a written per-hour plan beats improvising as the light changes. Build your numbers with the free ultra fueling calculator before race day.
The schedule runs on real clock time regardless of which distance you are running. At 7:00 PM, the course closes to anyone who has not started their second loop. The Gate 6 aid station has cutoffs at 8:00 PM and again at 11:00 PM, and the Clairemont Mesa aid station cuts off at 9:00 PM. The entire course closes at midnight. For the 50K, starting at 2:00 PM, that is a full 10 hour window; for the 25K, starting at 5:00 PM, it is 7 hours. Know which checkpoint cutoff applies to your pace and treat the 7:00 PM second-loop cutoff as your first real gate, not the midnight close.
The course starts and finishes at the East Fortuna Staging area off Hwy 52 and Mast Blvd, climbing the North and South Fortuna Mountains inside Mission Trails Regional Park. Expect exposed, sun-baked climbing in the early miles that gives way to sunset views from the summits, then genuinely dark singletrack for whatever portion of your race falls after nightfall. Bring a reliable headlamp with backup batteries or a spare light, since a meaningful stretch of most runners' races happens after sunset.
The 25K is a reasonable entry point if you have trained on real vert, since 3,600 feet over that distance is a serious but manageable ask and the 7 hour window is workable for a well-prepared first-timer. The 50K asks more: 7,200 feet of gain on a course that runs from full daylight into full darkness is a genuine test of night navigation and pacing discipline on top of the climbing itself. Whichever distance you pick, this is a hills-and-headlamp race in equal measure, so train the climbing and rehearse running technical trail in the dark before race day.
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<a href="https://runsummitline.com/guides/mission-trails-twilight-runs">The Mission Trails Twilight Runs course guide</a><iframe src="https://runsummitline.com/embed/race/mission-trails-twilight-runs" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Mission Trails Twilight Runs 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.
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