Thi Lor Su (Tee-lor-su) waterfalls is in the Umphang Wildlife Sanctuary of Tak province. It's the largest and highest waterfall in Thailand. Umphang is around a 6 hour road trip from Mai Sot along a very mountainous and winding road. The entrance to the National park is 30km from Umphang and then another 30km to the waterfalls along a mountainous mostly dirt road to the entrance to a 1.5km walking pathway carved through the wilderness with lots of steps.
Several years ago we attempted to visit the falls in November but the road to the falls was closed due to rain. It's officially closed June 1 to November 1 but the park service can close it anytime if there's any rain. The last trip we opted for a rubber raft boat trip down the rather rapid moving river running between sheer cliffs. Very scenic and unique.
There's different ways to get to Thilorsu and none without a lot of effort. Combination raft and guided trekking with a overnight in a tent is one option. We went with the self drive option with a 4-wheel rented vehicle. That in itself proved to be problematic. We wanted to fly to Mai Sot but I could not find a suitable rental. The closest city with a SUV rental was Phitsanulok. I rather like that city so a one night stay there was feasible. We drove from Phitsanulok to Umphang in one day, about 10 hours. With two drivers taking turns it was doable.
Umphang is a neat little mountain town. There's no western style hotels just guest houses and bungalows. Really good restaurants with Karen/Burmese food that I found really good.
We set out early for the falls. At the entrance to the National park they looked at our SUV-Toyota Fortuner 4-wheel drive and since it had AT (all terrain) tires they approved us entry for the 30km mostly dirt road to the waterfalls. If your vehicle is not suitable or the road conditions are not favorable you have to take one of the park trucks with a driver for 3000B RT to the 1.5km last leg, the walking/climbing path-quite a work out.
The park ranger said if we got stuck call and they would pull us out. Nice, but no where in the park did we notice any cell phone service. The 30km trip took about 2 hours. I was very cautious and got out of the vehicle several times to check the depth of streams and the conditions of the road. At some sections on coming traffic would be a problem but going in no one was going in the opposite direction. One of the park vehicles passed me going in and that was it. We were all alone. The occasional wild monkey looking down at us from a high tree. I did not see any snakes but the area is know for Burmese pythons.
We arrived and there was one other visitor. He did not stay long. It's was quite an impressive sight. We've been to many waterfalls in Thailand but this was unique. To say it was remote and hard to get to would be an understatement.
We could not spend more that a few hours at the falls since we had to hike back to the parking lot and then drive out on the dirt road and get out before it got dark. We basically had the falls to our self but did pass around 10-15 other visitors on the walking path going in as we were going out.
I had searched the net before this trip and found more bad information than good. Outdated and just wrong. I did not know about having to have AT tires but lucked out there. The guest houses want to sell you outfitter tours and provide false information. We called the park service for the straight skinny.
TAT did not get the logistics correct: https://www.tourismthailand.org/Attract ... fall--1188
LP with a lot of moaning about getting to the falls: https://www.tripadvisor.co.za/ShowUserR ... vince.html
Images: https://www.google.com/search?q=thi+lor ... guFtclgC3M: