The Amazean Jungle Thailand by UTMB drew its 2026 edition to a close in Betong, in the Yala province of southern Thailand, on Sunday with the FLOWER 20K and MIST 20K sending the festival's final waves out from the Mongkollit Tunnel start line. The event, the only Southeast Asian stop on the UTMB World Series since the format's expansion in the early 2020s, ran from 30 April through 3 May across five distances anchored by the Betong 100M flagship.
The headline 100M went off on Friday and crossed back into Betong's mountain town through the night and into Saturday morning, with the long-distance Running Stones on offer for the strongest finishes. The TUNNEL 100K and JUNGLE 50K filled Saturday's programme, and Sunday's two 20K starts close out the four-day timetable with shorter, runnable terrain that loops through the cross-border ridges separating Yala from Malaysian Perak.
Betong's appeal to UTMB's calendar planners has always been the singular character of its course. The Mongkollit road tunnel, the longest in southern Thailand at over 600 metres, doubles as the start arch and as a dramatic re-entry point on the longer loops; the route then climbs into rainforest singletrack that borders the Hala-Bala Wildlife Sanctuary and trades steep humid kickers with rolling jungle traverse. Course designers have consistently flagged the climate as the defining variable: tropical heat and high humidity push the 100M well beyond what its modest 5,500-metre vertical profile would suggest in cooler ranges.
The festival sits earlier in the calendar than most Southeast Asian trail events, and the front portion of the field this year leaned heavily on regional ultrarunners using Betong as a Running Stones top-up ahead of the UTMB Mont-Blanc finals lottery in November. UTMB's points and stones structure has continued to push regional races into a more strategic role on athletes' calendars, with Betong's long-distance status a particularly efficient route to qualifying weight for those based across the Asia-Pacific.
Organisers confirmed that the 2026 entry list reached its largest aggregate across the five distances, with the 20K races driving the bulk of the local participation surge. Betong, one of southern Thailand's least-visited regional centres outside trail-running circles, has used the UTMB festival as a tourism anchor for the long Songkran-to-Visakha Bucha shoulder window, and the local administration's continued partnership with UTMB Group runs to at least the 2027 edition. The 2027 dates are expected to be announced alongside the broader UTMB World Series calendar later in 2026.