The 4 mile St. George Island Bridge (designated State Road 300 from end to end, plus approaches) was built in 2002 (completed in 2004) when the two original bridges (cut by an island in the middle) that led to St. George Island, a small resort town 10 miles (16.1 km) from Apalachicola, Florida

Apalachicola, Florida

Apalachicola is a city in Franklin County, Florida, on US 98 about southwest of Tallahassee. The population was 2,334 at the 2000 census. The 2005 census estimated the city's population at 2,340...

 were deemed unsafe due to their old age. The new bridge, by bypassing the middle island, became the 3rd longest bridge in Florida. The north end of SR 300 is at US 98 (SR 30

State Road 30 (Florida)

State Road 30 is the mostly hidden Florida Department of Transportation designation for most of US 98 west of Perry, Florida to Alabama.In a 14-mile-long stretch west of Panama City, US 98 and SR 30 are separated by less than one mile , with SR 30 on Front Beach Road along the shore of the Gulf of...

) in Eastpoint

Eastpoint, Florida

Eastpoint is a census-designated place in Franklin County, Florida, United States. The population was 2,158 at the 2000 census.-Geography:Eastpoint is located at ....

. It was opened on February 27, 2004.

Initially, the bridge was designated State Road G1A by the Florida Department of Transportation

Florida Department of Transportation

The Florida Department of Transportation is a decentralized agency charged with the establishment, maintenance, and regulation of public transportation in the state of Florida. The department was formed in 1969. It absorbed the powers of the Florida State Road Department...

 while Gulf Beach Drive on the island east of the bridge was given the SR 300 designation. Later, the bridge and Gulf Beach Drive were both SR 300. More recently, Gulf Beach Drive lost its State Road designation, leaving only the St. George Island Bridge with the SR 300 designation. The eastern half of Gulf Beach Drive is now Franklin County Road 300.

"State Road G1A" was an analogue on the 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...

 to SR A1A on the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

. It is one of two x00 routes to not follow the numbering system - the other is SR 800

State Road 800 (Florida)

State Road 800 , locally known as Spanish River Boulevard/NW 40th Street, is a short east–west street in Boca Raton, Florida...

, a short connection over the Intracoastal Waterway

Intracoastal Waterway

The Intracoastal Waterway is a 3,000-mile waterway along the Atlantic and Gulf coasts of the United States. Some lengths consist of natural inlets, salt-water rivers, bays, and sounds; others are artificial canals...

 in Boca Raton

Boca Raton, Florida

Boca Raton is a city in Palm Beach County, Florida, USA, incorporated in May 1925. In the 2000 census, the city had a total population of 74,764; the 2006 population recorded by the U.S. Census Bureau was 86,396. However, the majority of the people under the postal address of Boca Raton, about...

. All other x00 routes are major cross-state diagonals.