Come Sunday, Sept. 1, and lasting the entire month, the lights of the St. Louis Arch will not shine at night to help birds safely navigate through the city.

What You Need To Know

  • The Arch's exterior lights will be turned off for the entire month of September

  • Light pollution can disorient birds, causing them to fly off path or into objects

  • St. Louis sits just below a bird migratory highway known as the "Mississippi Flyway"

May and September see high volumes of bird migration across our city as St. Louis sits below a major migration highway called the “Mississippi Flyway.”

Arch's lights go dark May and September

Jeremy Sweat, superintendent of Gateway Arch National Park, explains, “For over a decade, Gateway Arch’s exterior lights have been turned off for two weeks each May and September to help minimize the possible disorienting effect the lights may have on birds that migrate at night.”

With changes in migration patterns, the park decided it would extend turning the lights off for the entire month.

Migrating birds

According to the St. Louis Audubon Society, nearly 60% of North American songbirds and 40% of waterfowl will migrate during this time.

By working with Lights Out Heartland, a collaboration of organizations that partner to reduce light pollution during migratory bird periods across the U.S. Heartland, the hope is to provide migrating birds safe passage across the "Mississippi Flyway."

Birds migrating at night. (Photo by Missouri Department of Conservation)

To assist birds in safely navigating through our region, there are some things you can do at home. Here’s what you need to know to help.

The Arch’s exterior lights will be turned back on beginning Oct. 1, 2023, and the monument will be lit nightly thereafter.

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