Races
Flagstaff Sky Peaks 50 Miler
Arizona Snowbowl. Agassiz Loop first. Then high-country singletrack on the AZT.
50 mi+11,230 ft-11,230 ft15 hours7,317 ft to 11,482 fttech 9/106 stationsAgassiz LoopArizona SnowbowlUTMB IndexSeptember
Distance50 mi
Gain+11,230 ft
Loss-11,230 ft
Altitude7,317 ft to 11,482 ft
Technicality9/10
Air25°F to 65°F
- Start9,551 ft
- High11,482 ft
- Low7,317 ft
- Finish9,551 ft
- Flagstaff at mile 0.0
- Flagstaff Sky Peaks 50 Miler mile 10 at mile 10.0, cutoff 3 hours
- Flagstaff Sky Peaks 50 Miler mile 20 at mile 20, cutoff 6 hours
- Flagstaff Sky Peaks 50 Miler mile 30 at mile 30, cutoff 9 hours
- Flagstaff Sky Peaks 50 Miler mile 40 at mile 40, cutoff 12 hours
- Finish Arizona at mile 50, cutoff 15 hours
Terrain
Field, 2025 · 9-year sampleresults
Starters68
Finish rate90%
Median12:04
Sub-2461
Geometrycourse math
Steepest drop1,870 ft-18.8% over 1.9 mi
Night miles5 misunset near 19:00 local
Time over 10k ft6%
Longest climb2,264 ft26 mi at 1.7%
Weather at the cruxcourse math
At hour 7 of race, feels like 24 C (80 F).Sample of 7 race days, medium confidence.At hour 7 of race, apparent temperature P90 is 24 C / 76 F.
Course records
Men7:18:07Scott Traer
Women9:05:48Katalin Nagy
The cruxAgassiz Loop at 11,500 ft (near mile 33)
Course DNA
The Course
Flagstaff Sky Peaks 50 Miler runs 50 mi through Flagstaff, Arizona. +11,230 ft gain and -11,230 ft loss. Surfaces skew 90% trail / 10% doubletrack. Agassiz Loop at 11,500 ft. High point near 11,482 ft. Low near 7,317 ft. September temps run 25°F to 65°F. The course rewards patience early and punishes rushed descents after mile 25.
The Work
Train for 11,230 feet of climbing across 50 mi. Back-to-back long runs on trail. Practice power-hiking grades above 15 percent. 15 hours total means limited margin: rehearse fueling every 45 to 60 minutes and downhill eccentric work weekly. Technicality 9/10. Build a block that simulates the crux near mile 33.
Kit
September in Flagstaff, Arizona: plan for 25°F to 65°F. Mandatory shell if rain is in forecast. Headlamp with spare batteries if 15 hours pushes past dark. Poles help on sustained climbs above mile 13. Vest capacity for 2 liters minimum. Shoes matched to 90% trail: lugs for mud, rock plate if the course turns technical after mile 25.
Race Day
Hold effort through mile 13. The field often splits on the first big climb after mile 25. Agassiz Loop at 11,500 ft near mile 33 is where time is won or lost. Walk the steep pinches. Run the flats and gentle downhills. Crew at major aids: socks, calories, ice if hot. Transitions under 5 minutes when possible. Final third is 17 miles of fatigue management. Finish with reserve for the last descent.
Results
Flagstaff Sky Peaks 50 Miler finish lines.
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Sources (2)
- Field stats (2025): https://ultrasignup.com/results_event.aspx?did=120813
- Course record (M): https://ultrasignup.com/results_event.aspx?did=103843