Name: Under the Shadow of the Peaks Endurance Double
Start: 2026-09-19
End: 2026-10-03
Location: Flagstaff

About the Event

Endurance Double Challenge

Under the Shadow of the Peaks Endurance Double challenges runners to complete two signature Northern Arizona trail events in one season. Participants must first finish either the Flagstaff to Grand Canyon Stagecoach Line 100-Mile Solo Run or the 55K Solo Run on September 19–20, then return on October 3 to complete the full 26.2-mile Flagstaff Marathon. Finish both events and earn the special Endurance Double award! Entry is free! Set beneath the San Francisco Peaks, this endurance challenge combines historic Arizona Trail terrain with high-country forest running. The result is a multi-week test of pacing, recovery, and resilience at altitude. Completing both races requires more than endurance on race day—it demands smart recovery, steady pacing, and the ability to return to the trails after a major ultra-distance effort. SEPARATE REGISTRATION IS REQUIRED FOR EACH EVENT Registration for the Under the Shadow of the Peaks Endurance Double is required for participants' results tracking across both events.

Stagecoach Ultra

The Flagstaff to Grand Canyon Stagecoach Line Ultra follows portions of the Arizona Trail along the historic route once traveled by stagecoaches heading toward the Grand Canyon. Runners move through pine forest, open meadows, volcanic terrain, and rolling singletrack while navigating elevations that range from roughly 7,000 to nearly 9,000 feet. The 100-mile course features approximately 7,000 feet of elevation gain. The 55K offers a shorter but still demanding taste of Northern Arizona trail running. (runazt.org) Register for either the 100-mile solo or 55K solo here

Flagstaff Marathon

The Flagstaff Marathon takes runners through Arizona Nordic Village and surrounding Coconino National Forest trails. Marathon participants experience a mix of forest roads, singletrack, and doubletrack terrain at elevations above 8,000 feet. The cool mountain climate and steady altitude make the race both scenic and deceptively demanding. (flagstaffmarathon.com) Register for the Flagstaff Marathon here

Races Offered

Endurance

Sep 19, 2026

straighten

Distance — Endurance

terrain

Type — Running

timer

15 days remaining

Weather History

These values represent the 3-year monthly averages for September in Flagstaff.

thermostat Temperature

11.3° / 23.8°

wb_sunny Feels like

8.2° / 19.3°

light_mode Avg sunshine hours

11h 27m

water_drop Avg rainfall

0.7 mm

ac_unit Avg snowfall

—

air Avg wind speed

11.5 km/h (Light breeze)

opacity Sweat loss rate

Moderate

terrain Course conditions

Firm and slightly soft

sunny Max UV Index

Moderate (5.0)

humidity_mid Humidity

43.8%

wb_twilight Sunrise

06:09

nightlight Sunset

18:31

About Flagstaff

Learn more about the host city, Flagstaff.

Flagstaff is a city of over 75,000 people (2019) near the San Francisco Peaks mountain range of northern Arizona and the Grand Canyon. At an altitude of 6,990 ft (2,130 m), Flagstaff and much of the surrounding region are substantially cooler than the low desert that dominates the southern part of the state. Though still dry by east coast standards, enough rain and snow falls in the area to allow a forest of ponderosa pine trees to cover the landscape. Winters tend to be cold, and heavy snowfall is expected on an annual basis.