Cascade

The central Cascade Range cuts across Oregon and Washington as a belt of forested ridges, river valleys and prominent volcanoes. It divides moist Pacific slopes from the drier interior, producing dense conifer forest west of the crest and more open woodland and grassland eastward. Snow persists on high ridges into summer, while rivers cross the mountains through deep valleys and comparatively low passes.

Native communities used these passes for hunting, gathering and travel between the Columbia Plateau and the coast. Trails followed rivers, ridgelines and known snow-free corridors; high country supplied berries, game and obsidian-like exchange goods, while lower valleys supported winter villages. The mountains were difficult but not empty: their routes tied peoples across different ecological zones.

Volcanic activity repeatedly altered the landscape. The 1800 eruption of Mount St. Helens was recorded by Native oral traditions and by tree rings, and other Cascade peaks produced ash, lahars and landslides. Travel depended on the season, the state of river crossings and knowledge of unstable slopes. For preindustrial movement, the central Cascades formed a mountainous world of controlled passages rather than a continuous open frontier.