The former Wangka and Mawker camps were relocated to Phop Phra district in mid to late 1999. The camps were relocated due to security concerns as Burmese forces had repeatedly attacked both camps (in March 1998, Wangka camp was 80% burnt to the ground and 4 people killed, the camp had also been attacked in 1997 and 1996). The decision to locate the new camp near a Hmong village called Umpiem Mai was made by the Thai authorities; UNHCR was brought in to draw up a camp plan. The relocation took approximately 6 months to complete.
Umpiem Mai was initially a harsh environment with little tree cover, torrential rain and a cold climate. The camp is situated on very hilly terrain and there was a significant danger from soil erosion particularly during the rainy season. It was probably due to these factors that some people preferred not to make the move.
Over the first year, the camp saw some significant programmes initiated to ensure the integrity of the environment and to help promote a more pleasant living area. COERR and UNHCR surveyed the area and developed tree-planting programmes along with soil erosion projects. Water supply provided by ARC is available in all sections of the camp, however as new arrivals build houses higher up the slopes their availability to piped water is compromised. Nonetheless, the water supply for the camp is so far sufficient even during the hot season.
In January 2001, medical services, which were originally provided by MSF, were handed over to two other medical NGOs, ARC and AMI. ARC is responsible for preventative care such as health education and sanitation while AMI took over the curative medical care, which mainly involves the managing of the camp hospital.