Johnston Ridge Observatory gives visitors a front-row seat to the devastation of Mount St. Helen's eruption on May 18, 1980. Outside the facility is the plaza and overlook, allowing visitors to peer into the lava dome, crater, pumice plain, and land landslide deposit. Inside the observatory, visitors can see a 3D model of the mountain and eruption timeline, hear stories of survivors, and explore exhibits that describe our understanding of such earth-rattling events.
For visitors over 16, America the Beautiful Passes or other federal interagency recreation passes offer free entrance to the observatory.
It is best to leave pets at home when visiting the observatory, as they are not allowed inside the facilities or in the plaza area, and vehicles can get hot due to a lack of shade.
Be sure to fill your gas tank and bring plenty of water for the 52-mile journey from Castle Rock to the observatory.
The short Eruption Trail offers hikers interpretive signage and 360-degree views of the surrounding blast zone.
For additional context of the mountain, its history, and wildlife, stop at the Mount St. Helens Visitor Center in Castle Rock at the beginning of State Highway 504.
The road to the Johnston Ridge Observatory is the scenic State Highway 504, designated as Spirit Lake Memorial Highway. Johnston Ridge Observatory, and the surrounding blast zone, mark the end of the road. Whether you come from the north (Seattle) or south (Portland), I-5 will take you to the turn-off at Castle Rock, marking 52 miles to the observatory.
Johnston Ridge Observatory is open from mid-May to October, making the summer months the best time to visit. This is when the roads are clear, the weather is best, and programming, such as ranger talks and guided hikes, is plentiful. The summer season is also when a parking lot food cart is available for essential snacks, drinks, and lunch offerings.
The Johnston Ridge Observatory is named after volcanologist David Alexander Johnston, who was part of the U.S. Geological Survey monitoring team to assess changes on the mountain just before its eruption. The highly respected 30-year-old scientist was one of 57 people who did not survive the mountain's rapid and massive eruption in 1980.
