are in the Karen language. Transportation Highway 1090 (Mae Sot-Umphang) is the only road linking Umphang to other parts of Thailand. Another highway, Highway 1167, connects Umphang town to the Burmese border. Highway 1090, 164 km in total, has two lanes during much of the way and contains 1,219 curves, a number proudly displayed at numerous places in Umphang. It is one of the more unpleasant roads for those who suffer from motion sickness. The journey from Mae Sot takes from three to four hours. The journey from Bangkok takes about 12 hours. In the late-1970s, construction started on Highway 1117, (Khlong Lan-Umphang) a project that would have provided a connection from Amphoe Khlong Lan, Kamphaeng Phet province. It was part of a military effort to combat communist insurgency in the region. The project was shelved in 1987 pending an environmental study. About 115 km of the highway beginning in Khlong Lan was constructed, leaving the last 28 km on the Umphang side where it stopped at Umphang Wildlife Sanctuary in 1990. Efforts to finish this project surfaced a few times, but was eventually rejected due to the virgin forest in the path of the road. Another project linking Umphang to Amphoe Sangkhla Buri, Kanchanaburi Province was proposed in 2004, but was immediately rejected. Highway 1117 would have shortened the journey from Bangkok by five hours, and by-passed Mae Sot entirely. There is a municipal airport in Umphang. Scheduled flights here were scrapped due to low demand. Places Thi Lo Su Waterfall is the main reason people travel to Umphang. It is the largest waterfall in Thailand, with a height of about 200 meters and total width is about 400 meters. It is fullest during rainy season from June to November because of the larger water flow. However, during this period, road access to the waterfall is closed for safety reasons and some hiking is required. The peak season for tourism is in December and January when the water level is still high and the road to waterfall (25 km) is open to the public. Only cars with four wheel drive can pass this steep and slippery road. An alternative way to reach the waterfall is by whitewater rafting downstream along the calm section of Klong River and then continuing overland on foot or by car for another about 12 km. Travelling this way, two waterfalls dropping into Klong River