The Grand Gulf State Park is a state park and recreation area in Thayer, Missouri. It is sometimes called as the ?Little Grand Canyon?.

The Grand Gulf State Park features a forked canyon which is a remainder of an ancient dolomite cave system that has collapsed some centuries ago. There are still areas that are intact and are considered as the largest natural bridge in the state of Missouri, with its cavern roofs measuring 200 feet tall.

Declared as a National Natural Landmark in June 1971, the Grand Gulf State Park covers 322 acres. Visitors of the park can enjoy picnicking and hiking around the site, although there are no official trails that lead to the bottom of the canyon. Visitors are also advised to be extremely careful when trying to reach the bottom areas.