Guana Tolomato Matanzas (GTM) National Estuarine Research Reserve

Guana Tolomato Matanzas (GTM) National Estuarine Research Reserve is the newest reserve in the national system. It is geographically separated into a northern section, where the Tolomato and Guana rivers meet the Atlantic Ocean, and a southern section at the mouth of the Matanzas River.

The reserve is divided by the city of St. Augustine, Fla. It stretches approximately 30 miles north and 30 miles south of city, in St. Johns and Flagler counties.