Castle Rock (pop. 2,100) lies just west of I-5 along the Cowlitz River. The town is named for a 150-foot-high rocky knob that can be climbed by an easy-to-find path. The town was hit hard by the eruption of Mount St. Helens in 1980, when mud flows turned the Cowlitz into a raging torrent that washed out bridges and damaged or destroyed more than 200 homes.
In town is a memorial to Harry Truman, the old-timer who died at his Spirit Lake home when the volcano erupted and buried the lake in hundreds of feet of debris.
The Castle Rock Exhibit Hall and Visitor Information Center (147 Front Ave. NW, 360/274-6603, summer daily 9 a.m.–6 p.m., year-round Wed.–Sat. 10 a.m.–2 p.m., free) details the town and its connection to the Cowlitz River, the importance of the timber industry to the economy, and the impact of the 1980 eruption of Mount St. Helens.
The Castle Rock Fair on the fourth weekend of July is the big annual event, with a parade, stage shows, games, and carnival.
The Mount St. Helens Motorcycle Club sponsors Pro-Am TT Motorcycle Races all summer at Castle Rock racetrack.
Bicyclists come here for the Tour de Blast race in June and the Seattle to Portland bike race each July.
Castle Rock is the place to go for cheap Mount St. Helens–area lodging. Suitable motels include 7 West Motel (864 Walsh Ave. NE, 360/274-7526, $48 s or $55 d), which has the cheapest rooms in Castle Rock, Timberland Inn & Suites (206 Spirit Lake Hwy., 360/274-6002 or 800/900-6335, www.timberland-inn.com,$79 s or $89 d), and Mount St. Helens Motel (227 Spirit Lake Hwy., 360/274-7721, www.mountsthelensmotel.com , $65 s or 85 d).