San Mateo is an unincorporated community

Unincorporated area

In law, an unincorporated area is a region of land that is not a part of any municipality.To "incorporate" in this context means to form a municipal corporation, a city, town, or village with its own government. An unincorporated community is usually not subject to or taxed by a municipal government...

 in Putnam County, Florida

Putnam County, Florida

Putnam County is a county located in the state of Florida. The entire county makes up the Palatka Micropolitan Statistical Area. As of 2000, the population was 70,423. The U.S. Census Bureau 2009 estimate for the county was 72,893 . Its county seat is Palatka, Florida. The county is centrally...

, United States, located just southeast of the city of Palatka

Palatka, Florida

Palatka is a city in Putnam County, Florida, United States. The population was 10,033 at the 2000 census. As of 2004, the population recorded by the U.S. Census Bureau is 10,796. It is the county seat of Putnam County and includes East Palatka. Palatka is the principal city of the Palatka...

. It is on the east shore of the St. Johns River

St. Johns River

The St. Johns River is the longest river in the U.S. state of Florida and its most significant for commercial and recreational use. At long, it winds through or borders twelve counties, three of which are the state's largest. The drop in elevation from the headwaters to the mouth is less than ;...

.

Geography

It is located at 29.607°N 81.585°W, with an elevation of 72 feet (21.9 m). Businesses in the small town include the San Mateo Oasis, which is primarily a billiard and darts establishment that offers beer and wine for sale as well as water, soda and snacks and a hair salon that goes by the name, "Your Salon" which has been a fixture in the community for decades.