River systems of Thailand divides into two major branches, the " Tiền Giang" (Front River) and "Hậu Giang" (Back River). These in turn enter the South China Sea through nine estuaries. The following are the principal tributaries of Mekong River which flow through Thailand (tributaries entirely outside the Thai border not shown). The Mekong drains a considerable portion of northeast Thailand. In terms of Thai territory drained, it is second only to the Chao Phraya system. The Salawin River rises in Tibet (Tibetan: རྒྱལ་མོ་རྔུལ་ཆུ།) after which it flows through Yunnan, where it is known as the "Nujiang" River (), although either name can be
Hudson River flows south, taking in Beaver Brook and the outlet of Lake Harris. After its confluence with the Indian River, the Hudson forms the boundary between Essex and Hamilton counties. In the hamlet of North River, the Hudson flows entirely in Warren County and takes in the Schroon River. Further south, the river forms the boundary between Warren and Saratoga Counties. The river then takes in the Sacandaga River from the Great Sacandaga Lake. Shortly thereafter, the river leaves the Adirondack Park, flows under Interstate 87, and through Glens Falls, just south of Lake George although receiving no streamflow from the