| Tilton River | |
| Map Size: | 300 |
| Pushpin Map: | USA Washington |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of Tilton River in Washington |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Washington |
| Subdivision Type4: | County |
| Subdivision Name4: | Lewis |
| Length: | 29miles[1] |
| Discharge1 Location: | Cinebar, Washington |
| Discharge1 Min: | 50 cuft/s |
| Discharge1 Avg: | 979.8 cuft/s [2] |
| Discharge1 Max: | 1,200 cuft/s |
| Source1: | Gifford Pinchot National Forest |
| Source1 Location: | north of Morton |
| Source1 Coordinates: | 46.6564°N -122.2289°W[3] |
| Source1 Elevation: | 3035feet[4] |
| Mouth: | Cowlitz River |
| Mouth Location: | Lake Mayfield |
| Mouth Coordinates: | 46.5525°N -122.5344°W |
| Mouth Elevation: | 427feet |
| Basin Size: | 154sqmi[5] |
The Tilton River is a tributary of the Cowlitz River, in the U.S. state of Washington. Named for the first territorial surveyor for Washington Territory James Tilton (surveyor),[6] it flows for about 29miles, entirely within Lewis County.[1]
The Tilton River originates in the Cascade Range just north of Mount St. Helens and southwest of Mount Rainier. It flows south and west, joining the Cowlitz River in Lake Mayfield, near Mossyrock.[1]