Thi Lor Su Waterfall

Overview Thi Lor Su Waterfall (Thi Lo Su) is a large, remote waterfall in Umphang district of Tak province, northwestern Thailand, often described as one of the country’s most impressive cascades. It lies within a forested wildlife protection area and is noted for its multi-tiered drop and wide curtain of water.

What visitors find The waterfall is set in dense evergreen forest and offers a rainforest setting with pools and viewpoints close to the main cascade; flow and spectacle are at their peak during the rainy season. Trails and basic camping facilities exist near the site, and visitors commonly combine a visit with wildlife and nature activities in the surrounding sanctuary.

History Thi Lor Su is a natural feature long known to local communities and later designated part of the region’s protected areas to conserve the surrounding forest and watershed. Visitor infrastructure has been developed cautiously due to the remote location.

Location Situated in Umphang district, Tak province, the waterfall lies within a remote protected forest area accessible from the town of Umphang by a lengthy off-road drive or seasonal river approaches. The landscape is mountainous forest typical of northwest Thailand.

• Best time to visit: Flow is strongest during and shortly after the rainy season; conditions are driest and access easiest in the mid-dry season.
• Access: Located inside a protected wildlife area and reached via a long off-road route or by river and boat in some seasons, so plan transport in advance.

For many, Thi Lor Su is Thailand’s most impressive natural attraction, and though it takes some effort to reach, watching the waters thunder down a wide cliff is very rewarding. It lies within the Umphang Wildlife Sanctuary, a massive tract of virgin rainforest that is home to clouded leopards, serow (something between a goat and a deer) and several endangered bird species. Several ethnic hilltribes live in and around the sanctuary.

Exactly how big the falls are remains rather vague: estimates put the height at about 200 metres and the width at about 400 metres, though no precise figures are available. It certainly is an impressive sight seen from the viewing platform below, at the end of a delightful nature trail.

Timing is everything. The best time is November, after the rains, when the skies are clear and it is possible to clamber around the various pools at the base. Through the rainy season (June to October) so much water comes over the cliff that the viewing area is enveloped in spray and you cannot see the outline of the falls.

Getting to the falls. Confident drivers with a reliable 4WD vehicle can drive directly to the campsite at park headquarters from November to May, but most people, including the great majority of Thai visitors, prefer to take a tour that involves rafting and trekking to the campsite and staying overnight near the falls.

Thi Lor Su (Thi Lo Su) Waterfall is inside Umphang Wildlife Sanctuary in Tak province and is reached from Umphang district. Visitors normally travel to Umphang by road and then join an organized 4x4 or ranger-guided transfer on rough forest tracks into the sanctuary; road conditions are seasonal and the final approach can take several hours, so arrange transport or a tour from Umphang in advance.

• November and December are the best months: the falls are full after the rains, the skies are clear and the trails are drier.
• From roughly June to November the sanctuary road is closed to private vehicles and visits are by organised trip only; at the peak of the rains, spray can hide the falls and trips may be cancelled.
• From December to May, confident drivers with a sturdy 4WD can drive the rough track to the campsite, but most visitors prefer the raft-and-trek route through the Mae Klong canyon.
• Nights at the campsite are cold in the cool season, so bring warm layers.
• Book with an established operator in Umphang and check exactly what is included before you go.