Snoqualmie Pass: The Cascade Crossing

Snoqualmie Pass is the lowest crossing of the Cascade Range on Interstate Ninety's route, at about three thousand feet, modest by mountain standards, but the Cascades are a serious weather barrier and the pass can close or become treacherous with very little warning in winter. The climate on the west side is maritime: cool, wet, heavily forested with Douglas fir and western hemlock. The east side is rain shadow country, drier, colder in winter, hotter in summer, ponderosa pine and bunchgrass.

You can feel the transition in a few miles. The Snoqualmie people, whose name the pass carries, inhabited the river valley that runs west from this pass toward the Puget Sound lowlands. Snoqualmie Falls, eighteen miles west of the pass on the Snoqualmie River, is a sacred site in Snoqualmie cosmology, described in their oral tradition as the place where the sky and the earth came together at creation.

The Snoqualmie Tribe holds federal recognition and operates a casino and resort near the falls. The falls themselves, at two hundred sixty-eight feet, are higher than Niagara. The Milwaukee Road finished its railroad over this pass in nineteen oh nine, and the Sunset Highway opened through the pass in nineteen fifteen, near the original rail line.

Interstate Ninety replaced the old Sunset Highway in stages through the nineteen sixties and seventies. Before the pass was paved, crossing the Cascades in winter required chains, preparation, and a willingness to turn back. The highway has made the crossing routine enough that people sometimes forget what mountains are capable of.

The weather forecasting for this pass is done by the Washington State Department of Transportation around the clock in winter. The forecast is not always right.