Apalachee Bay is a bay in the northeastern Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

 occupying an indentation of the Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 coast to the west of where the Florida peninsula joins the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 mainland

Mainland

Mainland is a name given to a large landmass in a region , or to the largest of a group of islands in an archipelago. Sometimes its residents are called "Mainlanders"...

. It is bordered by Taylor

Taylor County, Florida

Taylor County is a county located in the state of Florida. As of 2000, the population was 19,256. The U.S. Census Bureau 2005 estimate for the county was 19,622 . Its county seat is Perry, Florida.- History :Taylor County was created in 1856...

, Jefferson

Jefferson County, Florida

Jefferson County is a county located in the U.S. state of Florida. As of 2000, the population is 12,902. The U.S. Census Bureau 2005 estimate for the county is 14,490 . Its county seat is Monticello, Florida....

, Wakulla

Wakulla County, Florida

Wakulla County is a county located in the U.S. state of Florida. As of 2000, the population was 22,863. The U.S. Census Bureau 2005 estimate for the county was 28,212 people...

 and Franklin

Franklin County, Florida

Franklin County is a coastal county located in the panhandle of the U.S. state of Florida. As of 2000, the population was 11,057. The U.S. Census Bureau 2005 estimate for the county is 11,177...

 counties. The Aucilla

Aucilla River

The Aucilla River rises close to Thomasville, Georgia, USA, and passes through the Big Bend region of Florida, emptying into the Gulf of Mexico at Apalachee Bay. The river is long and has a drainage basin of . The Wacissa River is a tributary...

, Econfina

Econfina River

The Econfina River is a minor river draining part of the Big Bend region of Florida, U.S.A. into Apalachee Bay. The river rises in San Pedro Bay near the boundary between Madison and Taylor counties, and flows through Taylor County to Apalachee Bay. It has a watershed of .- References :* Marth,...

, St. Marks

St. Marks River

The St. Marks River is a river in the Big Bend region of Florida. It has been classified by the Florida Department of Environmental Protection as an Outstanding Florida Water, and is the easternmost river within the Northwest Florida Water Management District....

 and Ochlocknee

Ochlockonee River

The Ochlockonee River is a fast running river originating in Georgia and flowing for before terminating in Florida.- Background :The Ochlockonee originates south of the town of Sylvester in Worth County in southwest Georgia emptying into Ochlockonee Bay, then into Apalachee Bay, in Florida...

 rivers drain into the bay. It is named for the Apalachee

Apalachee

The Apalachee are a Native American people who historically lived in the Florida Panhandle, and now live primarily in the U.S. state of Louisiana. Their historical territory was known to the Spanish colonists as the Apalachee Province...

tribe which lived between the Aucilla and Ochlocknee rivers until the 18th century. Most of the bay's coast is the St. Marks National Wildlife Refuge.