Contact USGS

  • About
  • Observatories
  • Activity
  • Education
  • Publications

Mount St. Helens National Volcanic Monument

The Mount St. Helens National Volcanic Monument is within the Gifford Pinchot National Forest and managed by the USDA Forest Service. The Monument was established in 1982 to designate 445 km2 (110,000 acres) around Mount St Helens for research, recreation, and education. Within its boundaries, the area that was impacted by the cataclysmic eruption of May 18, 1980 is left to respond naturally to all environmental factors.

The Monument offers many seasonal activities such as hiking, camping, fishing, snow sport, and ranger led educational programs. Information about recreational and educational activities can be found via the Monument's website. A permit is required for any person who wishes to hike above 4,800 ft, which includes climbing to the summit of the volcano.

Johnston Ridge Observatory

The Johnston Ridge Observatory is open seasonally and is located on Johnston Ridge in the center of the 1980 blast zone approximately 8 km (5 mi) north of the Mount St. Helens summit. The Ridge was named in honor of David Johnston, the USGS volcanologist who was on duty at the USGS Coldwater II observation point during the May 18, 1980 eruption. He was one of 57 people who lost their lives in the eruption. The Observatory building houses seismic, deformation, and other monitoring equipment that relays data to the USGS Cascades Volcano Observatory for analysis.

Ape Cave Lava Tube

Ape Cave is one of numerous lava tubes formed in the Cave Basalt about 1,895 years ago. The basalt lava flows have the form of pahoehoe flows that originated on the southwest flank of Mount St. Helens and flowed down the surface of older pyroclastic-flow deposits. The Ape Cave lava tube is the third longest lava tube (about 4 km or 2.5 mi) in North America. It is open year round and guided cave walks are offered daily during the summer visitor season. In winter months, a Sno-Park Pass is required to enter the area.