Coast Survey Base Marker - Florida Historical Markers on Waymarking.com

Marker text - 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 located 3.597 miles from the south marker, which is located approximately 300 feet southeast of Cape Florida Lighthouse.

History - A triangulation survey was conducted by the U.S. Coast Survey with men detailed from the U.S. Army and U.S. Navy. Alexander Dallas Bache, Superintendent of the U.S. Coast Survey, went to Key Biscayne in 1855 to take personal charge of the survey. The survey eventually included Key Biscayne, Biscayne Bay, the Florida Keys from south of Key Biscayne to the Marquesas Keys, and Florida Bay from the Keys to Cape Sable. The north base marker for Key Biscayne was reported lost in 1945 but was then discovered in 1970 as workers were clearing land for the Key Biscayne Golf Course. It was at first mistaken as a gravestone for someone named A. D. Bache. The underground granite block was found in place but the top monument was found on its side. The monument was reset over the underground mark in its original position as described below.

"THE STATION MARK IS A FINELY DRESSED GRANITE MONUMENT 16 INCHES SQUARE AND 3 FEET HIGH WITH A PYRAMIDAL TOP PROJECTING ABOUT 2 FEET ABOVE THE GROUND. THE VERTICAL FACES OF THE MONUMENT ARE INSCRIBED AS FOLLOWS: NORTH FACE - BASE NO 7 N., EAST FACE - U.S. COAST SURVEY, SOUTH FACE - A.D. BACHE SUPT., AND WEST FACE - 1855. THIS MONUMENT IS RESTING ON TOP OF A GRANITE BLOCK 3 FEET SQUARE AND 2 FEET THICK WHICH IS ABOUT 1 FOOT BELOW THE GROUND AND HAS A 3/4-INCH COPPER PLUG IN IT MARKED BY A CROSS."

(above information taken from original data sheet and Joan Gill Blank's book, Key Biscayne, 1996)

The monument and historical marker are located off the 10th hole along a golf cart path at the Crandon Park Golf Course on Crandon Drive, Key Biscayne. It is an easy walk from the parking lot.

The monument is benchmark AC3748 and can be logged.

Marker Number: unknown Date: unknown County: Miami-Dade Marker Type: Roadside Sponsored or placed by: Eastern Airlines in cooperation with Historical Association of South Florida Website: Not listed

Visit Instructions:
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Date Logged Log User Rating   12/24/2010 headbone visited it