Alexander Bache U.S. Coast Survey Line

The Alexander Bache U.S. Coast Survey Line extends over six miles, marked by granite blocks and monuments positioned to establish precise navigational reference points.

In January 1850, Alexander Dallas Bache and his team spent thirteen days measuring this line as part of the United States Coast Survey navigation improvement project.

The survey line represents a significant advancement in American maritime navigation, contributing to the development of accurate coastal mapping techniques in the 19th century.

Located at 8377 State Cabin Road on Edisto Island, the site features granite markers that indicate mile endpoints for geographic reference purposes.

The buried granite blocks at each endpoint of the line remain intact, serving as physical evidence of early American coastal surveying methods.

Location: Charleston County

GPS coordinates: 32.50560,-80.31030

Latest update: September 23, 2025 14:25