Northeast Fortieth Street — Microsoft's Interchange

Sal on SR 520 Eastbound: Seattle to Redmond · Oct 29, 2026 · 2m

Sal: Between Northeast Fortieth Street and West Lake Sammamish Parkway. Sal: In January 1985, Microsoft chose to move its headquarters from Bellevue to Redmond. Construction began that August, and the company moved into the 25-million-dollar facility on February 26, 1986, about two weeks before it went public. The site had once been home to chicken farms, back in the 1920s. Sal: The first campus had six buildings with room for 800 employees, growing to 1,400 by 1988. The buildings got sequential numbers, except for 7, held up by a delay in permitting that became indefinite. A pond between the…