Nan River
The Yom River (, , ) is a river in Thailand. It is the main tributary of the Nan River (which itself is a tributary of the Chao Phraya River). The Yom River has its source in the Phi Pan Nam Range in Pong District, Phayao Province. Leaving Phayao, it flows through Phrae and Sukhothai as the main water resource of both provinces before it joins the Nan River at Chum Saeng District, Nakhon Sawan Province.