Basalt Beauty in the Columbia River Gorge

One of the many basalt Waterfalls in the Columbia River Gorge

Towering cliffs, dramatic waterfalls, and rugged canyon walls throughout the Columbia River Gorge make it one of the Pacific Northwest’s most stunning landscapes. Beneath the captivating beauty lies an incredible geological story; the creation of those towering cliffs began with one of the largest volcanic events in Earth’s history.

Between 17 and 6 million years ago, enormous fissure eruptions opened across eastern Oregon, eastern Washington, and western Idaho. Unlike the steep volcanic mountains we often imagine, these eruptions came from long cracks in the earth. Lava poured out repeatedly, creating the Columbia River Basalt Group.

Some of the lava flow traveled hundreds of miles from Eastern Oregon and Idaho, following ancient river valleys westward. Individual flows could be more than 100 feet thick, stacking layer upon layer across the region. These repeated eruptions built the dark basalt foundation that now forms much of the Columbia River Gorge.

Millions of years later, the Columbia River cut through these hardened lava layers, exposing dramatic basalt cliffs and column formations visible throughout the Gorge. During the last Ice Age, the cataclysmic Missoula Floods further carved and sculpted the landscape, helping create many of the steep walls, waterfalls, and coulees seen today.

When you stand beneath the cliffs of the Columbia River Gorge, you’re looking at the remains of ancient rivers of lava, evidence of a volcanic story that reshaped the Pacific Northwest on a massive scale. The basalt of the Columbia River Gorge is more than just “rock”, it’s a reminder of the immense natural forces that shaped this incredibly gorgeous landscape. Every cliff face and canyon wall tells a story millions of years in the making, inviting visitors to explore the wild geology of the Pacific Northwest.

Towering Basalt Walls in the Columbia River Gorge