Washington 504
Washington 504
| Termini | I-5 (exit 49) and WA-411 in Castle Rock to the Coldwater Ridge Visitors Center at the Mount St. Helens National Volcanic Monument |
| Length | 48.6 miles |
| "Where does it go?" | WA-504 is the Spirit Lake Memorial Highway. It runs from Castle Rock through Toutle and Kid Valley to Coldwater Ridge. The highway east of Toutle was destroyed by the overview of debris into the Toutle River from the eruption of Mount St. Helens in 1980. The highway has been rebuilt high up from the river. |
| EB Miles | Eastbound down | Westbound up | WB Miles | Multiplex | Near City or Town |
County |
| 0.0 |  Huntington Ave |
48.6 | Spirit Lake Memorial Highway | Castle Rock | Cowlitz | |
| 0.1 |  |
48.5 | ||||
| 0.2 | Old Pacific Highway | 48.5 | ||||
| 2.0 | Tower Rd | 46.6 | ||||
| 5.6 | Seaquest State Park | 43.0 | ||||
| 10.6 | Slighty Rd | 38.1 | Toutle | |||
| 13.7 | Tower Rd | 35.0 | ||||
| 14.7 |  |
33.9 | ||||
| 23.2 | Sediment Dam Rd | 25.4 | Kid Valley | |||
| 48.6 | Coldwater Ridge Visitor Center | 0.0 | Mount St Helens National Volcanic Monument | |||