ST. LOUIS — The Great River Road, a 3,000-mile stretch of highway along the Mississippi River from Minnesota to the Gulf of Mexico, is turning 75.

The Mississippi River Parkway Commission is gathering Friday in St. Louis to celebrate the milestone. A ceremony on the significance, economic and tourism impact of the road is planned at the riverfront stage beneath the Gateway Arch.

The commission is a multi-state organization that promotes tourism along the Great River Road. Commission officials said travelers spend more than $25 billion annually in communities on the Great River Road, supporting thousands of jobs in 10 states.