About This Race
The 100K represents the core ultra distance at Ultra-Trail Australia, traversing the sandstone escarpments and eucalyptus forests of the Blue Mountains World Heritage Area. Starting and finishing in Katoomba, runners follow a demanding out-and-back route that showcases why this region has become one of Australia's premier trail running destinations. The course attracts a field of experienced ultrarunners, many using it as a stepping stone toward the 100-mile distance or as a challenging race in its own right. Finishers typically cross the line in 12-15 hours, navigating technical rock sections, river crossings, and sustained climbs throughout the day and into the night. The Blue Mountains present unique challenges: loose sandstone, steep staircases carved into cliff faces, and navigation through dense forest sections where concentration must remain sharp even as fatigue sets in. As part of the UTMB World Series, the race draws an international field while maintaining strong representation from Australia's ultrarunning community. The distance sits in a sweet spot for many runners—substantial enough to require serious preparation and respect, but manageable enough to avoid the extended recovery periods associated with 100-mile efforts. Most participants approach this as a seasonal goal race rather than a stepping stone, recognizing that the Blue Mountains terrain makes every kilometer count.
The route follows an out-and-back course from Katoomba, descending into the Jamison Valley before climbing back onto the plateau. Runners traverse the iconic Six Foot Track section, encounter the Golden Stairs (a notorious 900-step ascent), and pass through checkpoints at strategic locations including the historic Megalong Valley. The course combines fire trails with technical singletrack, requiring both physical endurance and technical skill as runners navigate rock scrambles and uneven sandstone formations.
Night running is almost certain for mid-pack finishers, adding navigation challenges through forested sections where headlamps illuminate towering eucalyptus and weathered rock formations. The return journey tests mental fortitude as runners retrace their steps, confronting familiar climbs with tired legs while managing the cooling temperatures of a Blue Mountains evening.
Location
Practical Info
Mid-May brings autumn conditions to the Blue Mountains with daytime temperatures typically 12-18°C (54-64°F), though exposed ridgelines can be significantly cooler. Night temperatures may drop to 5-8°C (41-46°F). Rain is possible, and fog occasionally settles into valleys, reducing visibility.
SYD - Sydney Kingsford Smith Airport
Katoomba offers a range of accommodation from budget hostels to boutique hotels, though booking well in advance is essential as the town is a popular tourist destination. The race weekend typically sees accommodation fill quickly, and some runners opt to stay in nearby towns like Leura or Blackheath with shuttle access to the start.