|Water code||US : 1528332|
|location||Olympic Peninsula , Washington (USA)|
|River system||Chehalis River|
|Drain over||Chehalis River → Grays Harbor → Pacific|
|source||Wynoochee Pass in Olympic National Park
|Catchment area||565 km²|
|Reservoirs flowed through||Wynoochee Lake|
The Wynooche River has a length of about 97 km and a catchment area of 565 km². It rises on the southern slopes of the Olympic Mountains in Jefferson County , but soon reaches Grays Harbor County . Before the river leaves the mountains, it is dammed to Wynoochee Lake . Below the reservoir, the river formed numerous meanders due to the debris carried along with it and the lower gradient . The Wynoochee River flows into the Chehalis River at Montesano .