Blast Zone & Waterfall Corridor

The observatory sits 5 miles from the 1980 crater at 4,314 feet — directly in the blast path of the lateral explosion that leveled 230 square miles of old-growth forest in four minutes. The visitor center documents the eruption in startling detail; the deck looks directly into the crater and the lava dome still visibly steams. The Eruption Trail (1.2 miles) traverses the blast zone.

A mountain inn and restaurant in Cougar, the last town before the monument's south entrance. The kitchen serves hearty Pacific Northwest comfort food — chili, burgers, house-made soups — to climbers, geologists, and day-trippers. The porch faces the tree line of the Gifford Pinchot National Forest.

A 2.5-mile lava tube formed 2,000 years ago during a prehistoric St. Helens eruption — the third-longest lava tube in North America. The lower cave requires a headlamp; the upper cave involves ladder sections. Temperature stays 42°F year-round. Lanterns available for rent at the trailhead.

Return for dinner and an overnight — the resort's rooms are simple but the mountain setting and dark sky make up for it. Cougar's population is under 500; the inn is the social center of the town after dark.

An octagonal stone observatory on a 700-foot basalt promontory above the Columbia River, built in 1917 as a monument to Oregon Trail pioneers. The view encompasses 30 miles of the gorge; on clear days Mount Hood appears to the east. Oregon's most visited National Historic Landmark.

At 620 feet, Multnomah is the tallest year-round waterfall in the US — a two-tier plunge visible from the Historic Columbia River Highway. The 2.4-mile round-trip trail climbs to the bridge between the tiers. The lodge at the base dates to 1925.