SR 520 floating bridge sentinel lights

The SR 520 floating bridge sentinel lights can be changed to recognize holidays and organizations and events of public significance.

The SR 520 floating bridge has four large towers, called “sentinels,” that mark the east and west ends of the world’s longest floating bridge. The tallest sentinel, at the bridge’s east end, rises 123 feet above the lake’s surface. These towers not only add an architectural flair to the bridge but also serve a critical function, allowing crews access to the bridge’s pontoon platform for maintenance.

Sentinel lighting

We illuminate the sentinels from dusk to dawn with LED lights. Teal is the standard color. Many color combinations are possible, which allows us to change the display color. Sentinel light changes are intended to recognize holidays and national and local campaigns, organizations and events of public significance. We cannot accommodate requests related to private events or political or religious events or campaigns.

photo of SR 520 floating bridge sentinel lit with blue and white LED lighting with Lake Washington in foreground and the sky at dusk.

How to request a color change

If you are interested in changing the sentinel lights for a public event or cause, please fill out the Sentinel Lighting Change Request Form (PDF 425KB) and submit it to

14 fish passage projects were completed in 2020

improving access to 54.2 miles of upstream habitat.

11,959 incidents responded to

by WSDOT’s incident Response teams during second quarter of 2021, 15% more than same quarter in 2020.

41 Pre-existing Funds Projects Advertised

during the eighth quarter of the 2019-2021 biennium.