Amazean Jungle Thailand by UTMB
Amazean Jungle Thailand by UTMB – BETONG 100M
Betong Mongkollit Tunnel → Betong Clock Tower
Race guide
Updated 18 July 2026
The BETONG 100M is the flagship distance of Amazean Jungle Thailand by UTMB, a 116 km loop that starts at the Betong Mongkollit Tunnel and finishes in town at the Betong Clock Tower. Over that distance runners climb 5,230 m of accumulated vertical, topping out at a high point of 1,163 m, on trails that thread through the deep jungle of Thailand's far south. It is a genuine hundred-mile-style challenge in miniature distance but not in difficulty: relentless up-and-down, humid air, and a long night out on the course. With cut-offs running from Friday evening all the way to midnight on Sunday, the BETONG 100M rewards runners who can keep moving steadily through heat and darkness rather than those who go out hard. The aid stations are lettered A1 through A9, several of them crew points, giving you regular targets to break the race into manageable pieces.
The course: a 116 km jungle loop
The route leaves the Betong Mongkollit Tunnel at 277 m and returns to almost exactly the same elevation at the Betong Clock Tower (277 m) after 115.9 km, so despite 5,230 m of total climb this is a course that gives everything back. The opening is gentle by the numbers, rolling from the tunnel to A1 Kapae Hulu School at 11.2 km (345 m) and on to A2 Suan Palm Resort at 24.8 km (309 m), letting you settle into a rhythm before the terrain steepens. From there the profile turns serious, climbing through A3 Ai Yoe So Village at 39.1 km (474 m) toward the high ground in the middle of the race. The back half unwinds through a string of aid stations spread every 8 to 16 km: A6 Fish Pond (71.1 km, 419 m), A7 Km.15 Village (79.4 km, 461 m), A8 Betong Hot Spring (89.8 km, 292 m), and A9 Thumthong Temple (105.8 km, 409 m) before the final descent back into Betong. Knowing the aid spacing matters here, because the longest gaps fall late in the race when you are most fatigued.
Where the race is won: the climb to the high point
The decisive stretch is the middle of the course, between A3 Ai Yoe So Village at 39.1 km (474 m) and A4 Ten-Thousand Flower Garden at 49.7 km (840 m). In roughly 10.6 km you gain the bulk of the climb toward the day's high point of 1,163 m — a sustained effort that lands you at the Saturday 05:00 cut-off checkpoint, likely in darkness. This is where an over-eager first 40 km gets punished, so it pays to arrive at A3 with legs still willing to grind uphill. From A4 the route steps down to A5 Piyamit Tunnel at 60.9 km (621 m) and continues its descent to A6 Fish Pond (71.1 km, 419 m), a long downhill that can quietly wreck quadriceps if you have hammered it. The lowest of the late aid stations is A8 Betong Hot Spring at 89.8 km (292 m), meaning the last 26 km still carries a net climb before the drop back to the Clock Tower. Treat the middle climb as the crux and manage your descending legs so they survive to the finish.
Pacing and fuelling to the cut-offs
The cut-off schedule defines the shape of a smart race. A2 Suan Palm Resort closes Friday 22:00, A4 Ten-Thousand Flower Garden Saturday 05:00, A5 Piyamit Tunnel Saturday 09:00, A8 Betong Hot Spring Saturday 18:00, A9 Thumthong Temple Saturday 22:00, and the Betong Clock Tower finish Sunday 00:00. The generous window to the finish means the bottleneck is really the early-to-mid checkpoints: banking time before A4 and A5 buys you breathing room for the long, hot Saturday that follows. Use the crew points strategically. A4 Ten-Thousand Flower Garden, A5 Piyamit Tunnel, A8 Betong Hot Spring, and the Betong Clock Tower are all crew-accessible, so plan drop-bag resupply and a change of socks or shirt at those stops. In jungle humidity your fluid and electrolyte needs will run high, so eat and drink at every aid station rather than waiting to feel depleted — the gaps of 10 to 16 km between stations are long enough that a fuelling mistake compounds fast. A6 and A7 in the back half are not listed as crew points, so carry what you need through that section.
Conditions to expect
This is a southern-Thailand jungle race, and heat and humidity are the defining environmental factors regardless of your fitness. The Friday-evening start into A2's 22:00 cut-off means a large portion of the 116 km is run through the night, so a reliable headlamp and spare batteries are essential — you will be moving in darkness across the high middle section of the course and again on the finishing stretch into Betong. Because the route repeatedly climbs and drops between roughly 277 m and its 1,163 m high point, expect meaningful swings in temperature and moisture: cooler, mist-prone air up high and thick, sweltering conditions in the lower valleys around the tunnels and hot spring. Waterproof your electronics, expect wet and slick footing on jungle trail, and manage chafing and foot maceration proactively. Runners who respect the heat, keep their electrolytes topped up, and stay patient through the night give themselves the best chance of reaching the Clock Tower before the Sunday 00:00 cut-off.
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Checkpoints & cut-offs
✓ Course data verified against the official source (2026-07-17) · official source
0 km · 277 m · —
11.2 km · 345 m · —
24.8 km · 309 m · Fri 22:00
39.1 km · 474 m · —
49.7 km · 840 m · Sat 05:00
60.9 km · 621 m · Sat 09:00
71.1 km · 419 m · —
79.4 km · 461 m · —
89.8 km · 292 m · Sat 18:00
105.8 km · 409 m · Sat 22:00
115.9 km · 277 m · Sun 00:00
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