Mount St. Helens Location: Washington State's Iconic Stratovolcano

Mount St. Helens rises in Skamania County, Washington State, 96 miles (154 km) south of Seattle and 53 miles (85 km) northeast of Portland, Oregon — the most accessible Cascade volcano for major metro populations.

Geographic Context

• Range: Cascade Volcanic Arc (BC to N. California)
• Coordinates: 46.2°N, 122.2°W
• Elevation: 8,366 ft (2,550 m) — post-1980 (pre-eruption: 9,677 ft)
• National Volcanic Monument: 110,000 acres, established 1982

1980 Eruption — Defining Event

• May 18, 1980, 8:32 AM: M5.1 earthquake triggered largest landslide in recorded history (0.7 cu mi)
• Lateral blast: 300+ mph, 600°F, 230 sq mi devastated
• Plinian column: 80,000 ft in 15 min, ash circled globe in 17 days
• 57 deaths: Including volcanologist David Johnston
• $1.1B damage (1980 $): Timber, infrastructure, agriculture

Visiting Today

• Johnston Ridge Observatory: 5.5 mi from crater, visitor center, films, trails (open May–Oct)
• Windridge Interpretive Site: Blast zone views, accessible
• Ape Cave: 2.5 mi lava tube (3rd longest N. America)
• Climbing Permit: Required above 4,800 ft (summer lottery, winter self-issue)
• Spirit Lake: Log mat still floating, ecological recovery laboratory

Monitoring & Hazards

Cascades Volcano Observatory (USGS) maintains real-time seismic, GPS, gas, thermal monitoring. Current status: Normal/Green. Next eruption: likely dome-building, not 1980-style lateral blast. Lahar (mudflow) risk remains for Toutle/Cowlitz/Columbia drainages.

Mount St. Helens: where geology's violence and nature's resilience are viscerally visible.