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Ultra-Trail Mount Yun by UTMB

Ultra-Trail Mount Yun by UTMB 100 Miles (161K)

100 miles (161K)
ultra100 milemountainforesttechnicaltrail

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Distance100 miles (161K)
Date16 Oct 2026
StatusOpen
Difficulty5/5

About This Race

The 161-kilometer distance at Ultra-Trail Mount Yun stands as the marquee event in this UTMB World Series race, offering runners a comprehensive traverse of the Mount Yun massif in southern China. This 100-mile challenge moves through varied mountain ecosystems, from dense pine forests at lower elevations to exposed ridgelines, with passage through the region's distinctive ice cave formations adding a unique geological element rarely encountered in trail ultras. Runners should approach this distance with proven 100-mile experience and comfort with extended efforts spanning 20 to 30 hours. The course demands technical footwork across shifting terrain types and mental fortitude through multiple day-night transitions. Mount Yun's remote character means long stretches between aid stations and limited bailout options once committed to certain sections. The October timing offers favorable conditions in this part of China, though mountain weather remains unpredictable. As a UTMB World Series event, the race attracts an international field and maintains strict qualification requirements tied to the UTMB Index system.

The 161K route provides a complete tour of Mount Yun's topography, transitioning between forested singletrack, rocky ridgeline traverses, and sections through the mountain's ice cave systems. Terrain varies from soft forest floor to technical rock gardens requiring careful foot placement. The mixed surface demands versatile footwear choices and adaptability as conditions shift throughout the route.

Location

Practical Info

Weather

Mid-October in the Mount Yun region typically brings moderate temperatures, though mountain conditions can shift rapidly with potential for rain and cooler temperatures at higher elevations.

Accommodation

Race headquarters and accommodation details are available through the official UTMB World Series event website, with lodging options likely concentrated near the start/finish venue.

Best For

ultra_runnersmountain_runnersexperienced_trail_runners

Notable Features

Mount Yun's ice cave formations distinguish this race from other UTMB World Series events, offering runners passage through rare geological features formed over millennia. The course showcases southern China's mountainous terrain to an international field, with cultural elements and regional character woven throughout the event experience. As part of the UTMB World Series, the race provides qualifying points and connects runners to the broader global trail running community.

Other Distances at This Event

20K (22K)

1,500m gain

The most accessible distance option while still delivering a genuine mountain trail experience. This 1 Running Stone route introduces runners to Mount Yun's natural beauty and cultural significance in a more manageable format.

50K (48K)

The 48-kilometer route explores Mount Yun's trail network through terrain that shifts between forested sections, exposed ridgelines, and passages through areas of cultural significance. Specific elevation gain data is not currently available, though runners should expect considerable vertical given the mountain setting and ultra designation. The course design reflects UTMB's approach to creating routes that balance physical challenge with opportunities to experience the landscape. Aid station locations and cutoff times follow the organization's standards for runner safety and support.

70K (68K)

The route traverses Mount Yun's mixed terrain, moving between established trails, forest paths, and technical sections that characterize the region's topography. Runners should expect a course that tests both technical skills and endurance management, though specific elevation profiles vary by year as the organizing team refines the route. As with all UTMB World Series events, the course will be marked to international standards with aid stations positioned at strategic intervals. The mixed terrain classification indicates runners will encounter variety throughout the distance, from runnable sections to more technical passages requiring careful footing.

100K (97K)

The 97-kilometer route covers the full range of Mount Yun's terrain features, from protected forest sections to exposed ridgeline passages. The course includes technical segments through ice cave areas that require careful footing and headlamp management during low-light hours. Specific elevation data has not been published, but the terrain mix indicates sustained climbing and descent across the mountain range.