Lam Sonthi (, ) is a tributary of the Pa Sak River. It originates at the Ruak and Phanghoei mountains in the border area of

Lam Sonthi Lam Sonthi (, ) is a tributary of the Pa Sak River. It originates at the Ruak and Phanghoei mountains in the border area of Amphoe Lam Sonthi, Lam Sonthi district, Lopburi province and Amphoe Si Thep, Si Thep, Phetchabun province. The river flows s ...

district, Lopburi province and Si Thep,

Phetchabun province Phetchabun ( th, เพชรบูรณ์, ) is one of Thailand's seventy-six provinces (''changwat'') lies in lower northern Thailand. Neighbouring provinces are (from north clockwise) Loei, Khon Kaen, Chaiyaphum, Lopburi, Nakhon Sawan, Phic ...

. The river flows southward as the backbone of Lam Sonthi district and joins with the

Lam Phaya Klang Lam Phaya Klang ( th, ลำพญากลาง, ) is a river of Thailand. It is a tributary of the Pa Sak River, part of the Chao Phraya River The Chao Phraya ( or ; th, แม่น้ำเจ้าพระยา, , or ) is the major ...

from

Muak Lek Muak Lek ( th, มวกเหล็ก, ) is a district (''amphoe'') of Saraburi province, Thailand. It occupies the province's easternmost part, in the Dong Phaya Yen Mountains which divide the central and northeastern regions. Originally a for ...

district, Saraburi province. Then the watercourse flows ahead to west and tributes the Pa Sak River in Chai Badan. It is long.

References

Sonthi {{Thailand-river-stub