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I-90 - Snoqualmie Pass East - History

Long before the early explorers came to the Northwest, Native Americans on both sides of the mountains carved foot trails across the Central Cascades, including Snoqualmie Pass, to hunt deer, elk and other game animals, fish for salmon, and gather berries. They also traveled to this area to gather wild plants for food, medicinal purposes, and basket weaving. Pacific Northwest tribes like the Snoqualmie Indian Tribe and Yakama Nation, used foot and horse trails across the Central Cascade mountains for trading as it had the lowest pass elevation in the territory.

How did people originally travel across Snoqualmie Pass?
In 1854, the United States Government began scouting the Cascades for railroad routes and wagon trails. In 1865, construction started on a wagon road on the west side of the pass to lure settlers to Seattle. But on the east side, just a trail existed and settlers often used rafts and barges to cross Lake Keechelus. Finally by 1867, the wagon road stretched from Seattle to Ellensburg. In 1884, a toll was placed on the road to help pay for its maintenance. By 1905, harsh winters and flooding forced settlers to rebuild the road several times to provide a safer and passable road.

What route did people travel over Snoqualmie Pass?
In 1905, the first automobile drove over Snoqualmie Pass, but the road was far from adequate. That same year, the Washington State Department of Highways was created and plans to improve the road over the pass soon began. In partnership with King and Kittitas Counties, the road was upgraded to promote the 1909 Alaska –Yukon - Pacific Exposition in Seattle, which promoted an auto race across the pass. In 1915, a new two-lane road was built, called Sunset Highway, which created a permanent transportation route that connected eastern and western Washington. Later in 1926, this highway was rebuilt on the abandoned Milwaukee Railroad right-of-way.

How did the route over Snoqualmie Pass develop?
It wasn't until 1931 that the Department of Highways could keep the road open through an entire winter. In 1934, the highway was renamed Public State Highway No. 2, and an ambitious campaign to pave a 17-mile stretch of roadway at the summit began. A few years later, the road was renamed US Route 10, a rest area, Travelers’ Rest, was built in 1938, and the Lake Keechelus and Airplane Curve Snowsheds were built in 1950.

When was I-90 created?
In the 1950's and 1960's, US Route 10 was widened to four lanes. Also during this time, state highways were renumbered to meet the American Interstate Highway System, creating Interstate 90. In the 1970's, major highway projects near the pass were completed that replaced concrete pavement, straightened roadway curves, and made other safety improvements. The efforts in the 1970's kept traffic moving across Snoqualmie Pass for the next 30 years.

What is the next step for I-90?
In 1999, WSDOT began studying a 15-mile portion of I-90 between Hyak to Easton. In 2005, the Legislature approved the Transportation Partnership Account gas tax, which secured $551 million for WSDOT to improve the first five miles of the corridor by adding a lane in each direction, replacing deteriorating concrete, adding and replacing bridges and culverts, extending chain up/off areas and replacing the snowshed just east of the Snoqualmie Pass Summit with another structure to reduce winter avalanche closures. This portion of the project is scheduled to be complete in 2017. 

Despite facing tough funding choices and a lean budget, the 2012 Legislature recognized the importance of the project and confirmed their support by committing construction funds into the 2013-2015 biennium. This $106 million will support Phase 2A of the project and continue work for two additional miles from the Keechelus Dam vicinity to the Stampede Pass interchange. The Phase 2A design package, which WSDOT engineers are currently designing, will include the first wildlife crossing over the highway in the corridor and is scheduled for construction in 2015.