The Ann W. Richards Congress Avenue Bridge is one of Austin's most iconic bridges, crossing Lady Bird Lake at Congress Avenue. The bridge was originally constructed in its modern form in 1910, revising and remodeling prior bridge structures dating as far back as 1869, and originally crossed the Colorado River before its impounding at Lady Bird Lake. In 2006, the bridge was renamed in honor of Ann W. Richards, the state's 45th governor and one of Austin's most prominent citizens. It is best known as the home of the world's largest urban bat colony, with up to 1.5 million Mexican free-tailed bats residing underneath the bridge each summer. Tourists can observe bat populations flying at dusk for feedings during the summer months, traveling away from the bridge over Lady Bird Lake to the east. An information kiosk on the bridge's bat population is offered along the lake's northern banks at the east end of the bridge. Map