Borneo Ultra Trail Marathon (BUTM): Race Guide
What is the Borneo Ultra Trail Marathon?
The Borneo Ultra Trail Marathon (BUTM) is Sabah's flagship trail race, held each April in the Kiulu Valley. It is ITRA-rated and a UTMB World Series qualifier, with distances of 9, 34, 50 and 103 km on jungle trails.
What is the Borneo Ultra Trail Marathon?
The Borneo Ultra Trail Marathon (BUTM) is Sabah's leading trail and ultra-distance running event. Based in the Kiulu Valley, about 45 km from Kota Kinabalu in the foothills of the Crocker Range, it takes runners off the road and into the rainforest for a true wilderness challenge.
What sets BUTM apart from Sabah's other big races is its international standing in the trail community: it is rated by the International Trail Running Association (ITRA) and serves as a UTMB World Series qualifier, putting it on the radar of trail runners worldwide.
When and where is BUTM held?
BUTM is run annually in April in the Kiulu Valley, deep in the Crocker Range foothills. The valley's rivers, ridges, and jungle trails provide the natural arena for the race. April sits within Sabah's drier season, but runners should still prepare for humidity, rain showers, and slippery footing on the trails.
Distances and categories
BUTM spans the full range of trail running, from a short taster to a serious mountain ultra:
| Distance | Best for |
|---|---|
| 103 km | Experienced ultra runners chasing UTMB points |
| 50 km | Established trail runners stepping up to ultra |
| 34 km | Trail runners building distance |
| 9 km | Newcomers wanting a first taste of jungle trail |
The UTMB and ITRA connection
For serious trail runners, BUTM's biggest draw is its status as a UTMB World Series qualifier. Finishing here can earn the qualifying credentials needed to enter the Ultra-Trail du Mont-Blanc, one of the most prestigious races in the sport. Its ITRA rating confirms the course has been assessed for distance and difficulty to international standards.
What the terrain is like
BUTM is a genuine off-road event. Runners tackle jungle trails, river crossings, and highland ridges through the Crocker Range foothills. Underfoot conditions range from packed earth to mud and rock, and the rainforest brings heat and humidity that can sap energy fast. This is a course where navigation, footing, and heat management matter as much as raw speed.
Preparing for BUTM
Trail-specific preparation is essential. Road fitness alone will not carry you over technical jungle terrain and climbs.
Build strength on hills and technical descents, practise running in heat and humidity, and rehearse with the mandatory kit and hydration you will carry. Recce the river crossings if you can, and plan your nutrition for the longer distances where time on feet stretches into many hours.