| Green River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Washington |
| Subdivision Type3: | Counties |
| Subdivision Name3: | Lewis, Skamania, Cowlitz |
| Length: | 37.4miles |
| Discharge1 Location: | near Kid Valley[1] |
| Discharge1 Min: | 34.2cuft/s |
| Discharge1 Avg: | 479cuft/s[2] |
| Discharge1 Max: | 14500cuft/s |
| Source1: | Near Spirit Lake |
| Source1 Location: | Gifford Pinchot National Forest, Lewis County |
| Source1 Coordinates: | 46.3006°N -122.0925°W[3] |
| Source1 Elevation: | 4765feet |
| Mouth: | North Fork Toutle River |
| Mouth Location: | Toutle, Cowlitz County |
| Mouth Coordinates: | 46.3728°N -122.5825°W |
| Mouth Elevation: | 741feet |
| Basin Size: | 131sqmi |
The Green River is the largest tributary of the North Fork Toutle River in the U.S. state of Washington. Situated near Mount St. Helens in the Cascade Range in the southern part of the state, it flows generally west through Mount St. Helens National Volcanic Monument and industrial timberlands for 37.4miles. The river drains more than 130mi2 in parts of three Washington counties: Skamania, Lewis, and Cowlitz.
As with most other parts of the Toutle River and Cowlitz River systems, the upper part of the Green River was heavily affected by the 1980 eruption of Mount St. Helens.
It rises from snowmelt on the opposite side of a ridge from Spirit Lake, in the Gifford Pinchot National Forest in Skamania County. The river initially flows north, but turns northwest after the confluence with Grizzly Creek. Turning west, it crosses into Lewis County, then back south into Skamania, and almost immediately afterwards flows into Cowlitz County. Shultz Creek enters from the left then Devils Creek from the right. The river empties into the North Fork Toutle River near the unincorporated community of Toutle.[4]