Gateway Arch goes dark through September

The Gateway Arch has gone dark and will stay that way throughout September. 

Exterior lights that normally light up the giant structure will remain turned off as numerous species of birds fly south for the winter. 

Ducks, geese, and other birds migrate along four aerial routes. 

They include the so-called “Mississippi Flyway,” which roughly follows the path of the Mississippi River. 

The National Audubon Society says that most birds migrate at night due to cooler temperatures and because the moon and stars help with navigation. 

The Gateway Arch exterior lights will be turned back on October first.