History of Snoqualmie Pass in Timeline

By Popular Timelines Editorial Team · Updated: April 16, 2026

Snoqualmie Pass is a mountain pass in Washington State that facilitates Interstate 90's passage through the Cascade Range. Located on the border between Kittitas and King counties, the pass summit sits at an elevation of 3,015 feet (919 m). It's a crucial transportation route through the mountains.

1909: Railroad Line Completion

In 1909, the Chicago, Milwaukee, St. Paul and Pacific Railroad (the "Milwaukee Road") completed a line through Snoqualmie Pass as part of its Pacific Extension.

1914: Snoqualmie Tunnel Construction

In 1914, the original rail line was replaced by the 2¼-mile Snoqualmie Tunnel, running from Hyak to Rockdale.

1915: Sunset Highway Opening

In 1915, the Sunset Highway was opened through Snoqualmie Pass, near the original rail line.

1927: U.S. Route 10 Designation

In 1927, the road over Snoqualmie Pass became U.S. Route 10.

1931: Winter Plowing Begins

In 1931, the road over Snoqualmie Pass, U.S. Route 10, began to be plowed and kept open during winter.

1933: First Ski Hill Cleared

By 1933, the first alpine ski hill was cleared at Snoqualmie Pass.

January 21, 1934: Seattle Ski Park Opening

On January 21, 1934, the Seattle Parks Department opened the Seattle Ski Park at Snoqualmie Pass, the first municipally owned ski facility in the United States.

1934: U.S. Route 10 Paved

In 1934, U.S. Route 10, the road over Snoqualmie Pass, was finally paved.

1940: Closure of Seattle Ski Park

In 1940, the city government closed the Seattle Ski Park, which was located at Snoqualmie Pass.

June 24, 1946: Spokane Indians bus accident

On June 24, 1946, seven players and their manager on the Spokane Indians minor league baseball team were killed in a bus accident on the Snoqualmie Pass Highway.