Snoqualmie Pass, Rail mountain pass in Washington, United States.

Snoqualmie Pass is a mountain crossing through the Cascade Range at about 920 meters elevation that links eastern and western Washington State. Interstate 90 runs through this passage, making it the primary route for traffic between both sides of the state.

The Chicago, Milwaukee, St. Paul and Pacific Railroad (the Milwaukee Road) completed its Pacific Extension line through Snoqualmie Pass in 1909. In 1914 this grade was replaced by the 2¼-mile Snoqualmie Tunnel, running from Hyak west to Rockdale about 400 feet below the pass. The rail line was abandoned in 1980, and the tunnel now carries bicyclists and hikers as part of Iron Horse State Park.

The pass and the summit community take their name from the Snoqualmie people of the valley to the west. Hudson's Bay Company trappers and traders were active in the Snoqualmie and Yakima valleys in the early 19th century and knew of the pass. In 1841 A.C. Anderson drove cattle across the Cascades via a route he called "Sinahomish Pass".

The pass receives heavy snowfall annually, so drivers should carry tire chains and check road conditions during winter months. Regular updates on traffic conditions are important, especially during winter season and on weekends.

The 2¼-mile Snoqualmie Tunnel, bored in 1914 from Hyak west to Rockdale about 400 feet below the pass, carried Milwaukee Road trains until the line was abandoned in 1980. It now forms part of Iron Horse State Park, a multi-use trail for cyclists and hikers.