Hawaii has the most extensive coral reefs in the U.S., with vibrant and diverse reef systems around the islands.

Hawaii is home to the largest and most extensive coral reefs in the United States, spanning around its islands. These reefs are located in the Pacific Ocean and are famous for their high biodiversity, including various species of fish, corals, and marine life. Florida also has significant coral reefs, especially around the Florida Keys, but Hawaii's reefs are more expansive and ecologically diverse due to the unique environmental conditions in the region. Texas and California have coastal ecosystems but are not known for large coral reef systems.