Most people are surprised to learn that rich coral reef communities can be found in the northwestern Gulf of Mexico - only 105 miles due south of the Texas/Louisiana border. Over 100 years ago, offshore fisherman discovered a number of shoals that supported huge fish populations. In the 1930s, some of these features were finally charted. Geologists also began to study two of the shallower features, which were called the Flower Garden Banks, due to the brightly colored rocks (which were later discovered to be coral) that sometimes snagged fishermen's hooks and boat anchors. It wasn't until the 1960s that scientists and scuba divers discovered the banks were composed of massive, continuous coral reefs, with large schools of tropical fish, sea turtles, sharks, and large impressive creatures such as manta rays and whale sharks. It turned out that the banks were perched atop two salt domes that rise from the ocean floor. These reef structures represent the northernmost coral reefs found in the United States.

The rich biological diversity and breathtaking beauty of the Flower Garden Banks prompted researchers and recreational divers to seek protection for the Flower Gardens. They launched a 20-year effort that ended up with the creation of the Flower Garden Banks National Marine Sanctuary (FGBNMS) in 1992.

In October 1996, Congress expanded the Sanctuary by adding a small third bank. Stetson Bank is also a salt dome, located about 70 miles south of Galveston, Texas. Cooler winter temperatures here do not allow coral to thrive, but assemblages of associated animals and plants can be found living among the odd geologic formations found there.

FGBNMS is one of twelve national sanctuaries operated under the National Oceanographic and Atmospheric Administration's (NOAA) National Ocean Service (NOS) National Marine Sanctuary program