Unlike treks further north around Chiang Mai, treks around Umphang are more about wilderness than hill-tribe villages and are far more popular with Thai tourists than farangs. The big highlight is the three-tiered, 200m-high Tee Lor Su Waterfall (Nam Tok Thilawsu), star feature of the Umphang Wildlife Sanctuary (entry B200), which, unusually for Thailand, flows all year round. It’s at its most thunderous just after the rainy season in November, when it can extend to a dramatic 400m across. During this period you can swim in the beautifully blue lower pool, but trails can still be muddy, which makes for tough going; trek leaders recommend wearing rubber boots (best bought in Mae Sot, as they’re hard to find in Umphang). One stretch of the route becomes so muddy during and just after the rainy season that it’s impassable to human feet and needs to be done on elephant-back, a pretty uncomfortable ride of three to four hours. Nonetheless, the best season for trekking is November through February, even if the nights get pretty chilly. From December to April (the dry season), it’s usually possible to climb to one of the waterfall’s upper tiers, mud permitting. Around the falls, the vegetation is mainly montane forest, home to numerous varieties of orchid, and plenty of commonly encountered monkeys and hornbills, plus an elusive band of wild elephants.
Access to the falls is strictly controlled by national park rangers, who forbid people from taking food or plastic water bottles beyond the ranger station and campsite, which is 1.5km from the falls. As yet, the number of visitors is reasonably small – except on public holidays, during school holidays and on some weekends, when Thai trippers flood the area. Visitors reach Tee Lor Su Falls either via a fairly challenging combination of rafting and walking, or by using the road to the ranger station (4WD only), which may be impassable between June and November. If you can take this road route, you’ll only have to walk the 1.5km route from the station to the falls. Some tour operators offer the car-plus-hike option as a day-trip from Umphang, usually throwing in a rafting session as well.
A typical trek to Tee Lor Su lasts three days and follows something like this increasingly standard itinerary. Day one: rafting down the Mae Khlong River via Tee Lor Jor Falls and some striking honeycombed cliffs; then a 9km trek (3hr) to the official campsite near Tee Lor Su Falls. Day two: morning at the falls, then a two-hour trek to a homestay at the Karen village of Khotha. Day three: a three-hour elephant ride (or trek) to Mae Lamoong junction; return to Umphang by car. Some trekkers find the three-day itinerary too baggy, with quite a lot of empty time at day’s end (bring a book), so if you want a more challenging experience try to persuade your trekking agency to cover the same itinerary in two days. Prices start at about B2700 per person (B3200 with elephant riding) for the two-day Tee Lor Su trek (minimum two people) or B3000/3500 for three days. Add about B1000 per person for treks arranged in Mae Sot. Prices do vary between operators: smaller outfits can’t afford to undercut the big operators and cost savings can mean lower wages – and morale – for guides. In Umphang the best time to contact trek leaders at the smaller outfits is often after about 4pm, when they’ve returned from their last trip. Guides should provide tents, bedrolls, mosquito nets and sleeping bags, plus food and drinking water; trekkers may be asked to help carry some of the gear.
Although Tee Lor Su is the most famous destination in the Umphang area, other programmes are available on request. From June to October there’s whitewater rafting from the Karen village of Umphang Khi via the forty-plus rapids of the Umphang River, which can also include a fairly long trek and a night in the village. Alternatively, there are one- and two-day rafting trips to Thi Lor Leh Falls, which involve four to eight hours’ rafting (depending on water levels) via a series of cataracts along the Mae Khlong River, and the possibility of a seven-hour trek on the second day. For bird-spotting, ask about trips to Thung Yai Naresuan.