Historic Markers Across Florida

Coast Survey Base Marker

Marker ID: HASF 
Location: on Key Biscayne, Miami, FL
County: Miami-Dade
Waymark: None


The Key Biscayne North Base Marker was placed here in April of 1855 by the U.S. Coast survey team, under the direction of Alexander Dallas Bache, the great-grandson of Benjamin Franklin and Superintendent of the Coast Survey. The survey was done by triangulation, a mathematical system using triangles to compute various distances from a few measured lengths, known as bases. Using these bases the coast of South Florida was mapped for navigational purposes. This marker, at the north end of the Key Biscayne base, is 3,597 miles from the south marker, which is located approximately 300 feet southeast of Cape Florida Lighthouse.

Sponsored by Eastern Airlines in cooperation with the Historical Association of Southern Florida


City: Miami, FL