Mountains to Sound Greenway: route guide

The greenway is the I-90 corridor between Seattle on Puget Sound and Ellensburg on the dry east side of the Cascades. West of the mountains the road runs past Lake Washington, Mercer Island, Bellevue and Issaquah; the climb starts around North Bend and tops out at Snoqualmie Pass (921 m). East of the pass the landscape changes fast: Cle Elum, then the Yakima River valley into Ellensburg.

Coordinates here are approximate, centred on the corridor near Snoqualmie Pass at 47.4100, -121.3800. Use offline maps: cell coverage is patchy in the pass and along the upper Yakima.

Treat the drive as three stages. The urban stage (Seattle to Issaquah) is freeway with traffic; the mountain stage (North Bend to Cle Elum) is where the scenery and the stops are; the eastern stage (Cle Elum to Ellensburg) is open country with a couple of good detours.

The single stop most people rate highest is Snoqualmie Falls, an 82 m waterfall with a free viewing platform and a paid car park in summer. Nearby Snoqualmie and North Bend add a historic rail depot and easy river trails. At the pass itself, the Pacific Crest Trail crosses the highway, and the ski area runs lift-served terrain in winter. East of the pass, Lake Keechelus and Lake Kachess sit beside the road, and Cle Elum is the last full-service town before Ellensburg.

Late spring to early autumn is the window for hiking: trails at the pass are usually clear of snow from June into October, and the wildflower weeks fall in July and August. Summer weekends bring the heaviest traffic, especially westbound on Sunday afternoons, so leave Seattle before 8am or after 7pm if you can.

Winter turns the corridor into a ski route. Snow tires or chains are commonly required over Snoqualmie Pass in winter, and the state can close the highway for avalanche control or crashes; check conditions before you commit. Spring and autumn give you the road without the crowds, but expect rain west of the crest and wind east of it.

Seattle and Bellevue have the widest choice and the easiest access to the west end. Issaquah and North Bend are the practical bases for the falls and the closest trails, with motels and short-term rentals rather than big hotels. At Snoqualmie Pass there is limited lodging, mostly tied to the ski season, so book early if you want to sleep at the summit.

East of the pass, Cle Elum and Ellensburg are cheaper and quieter, and Ellensburg works well as a stop if you are continuing to Yakima, the Tri-Cities or Spokane. Camping is available in the national forest along the corridor; some sites close with the first snow.

You need a car for the full route. King County Metro buses reach North Bend, and ski-season charter buses run Seattle to Snoqualmie Pass, but no scheduled service stops between Bellevue and Ellensburg, so the middle of the greenway is car-only. Fill the tank in North Bend or Cle Elum; services at the pass are limited.

Carry water, layers and rain gear even in summer, since weather at 921 m differs from Seattle. The Cascades are black bear country: store food properly, make noise on trails and ask a ranger for local advice. A Northwest Forest Pass or day fee may apply at some trailheads (2026 estimate); check at the site.