NH Stone Wall Mapper Launched

The NH Geological Survey (NHGS), at the NH Department of Environmental Services (NHDES), is launching a new interactive “New Hampshire Stone Wall Mapper” that will enable the public to use this online tool to map the state’s historic stone walls. This crowd-sourcing map is made possible through a $14,487 grant from the NH Charitable Foundation. The grant will help further NHGS’ mission to provide the public with information on the state’s landforms and to promote earth science education.

The New Hampshire Stone Wall Mapper uses Light Detection and Ranging (LiDAR) images across NH to map the stone walls, even in areas that are completely forested. LiDAR provides a detailed map of land surface elevations representing the “bare earth” as though treeless, rather than the aerial satellite imagery we are accustomed to. The NH Stone Wall Mapper provides an opportunity for the public to trace stone walls right onto LiDAR images while panning and zooming across the state on their computer screens. The mapping interface has been designed to be easy to use and only requires access to a web browser and the internet. UNH GRANIT developed and is hosting the crowdsourcing application.  

According to Rick Chormann, NH State Geologist, the project is designed to stimulate the public’s fascination with NH's legacy of stone wall building and help ensure their care and preservation. “We will fuse new technology with New Hampshire history to create a unique cultural heritage preservation asset and learning experience,” says Chormann. “Over time we hope to build a network of volunteers mapping wall-to-wall across the entire state.” 

The project’s maps of stone walls will provide an inventory that will support efforts by the state and local communities to monitor and preserve these iconic symbols of our heritage. New Hampshire state law affords limited protection to stone walls, but the provisions are weak and enforcement is difficult. Insensitive repairs, removal or theft for resale elsewhere, road widening and new construction all take their toll on the state’s stone walls.

“Generations of farmers and masons built thousands of miles of stone walls out of New Hampshire granite, and today those walls are vanishing,” said Elizabeth H. Muzzey, director of the NH Division of Historical Resources and state historic preservation officer. “Identifying what remains is the important first step of preserving them for generations to come.”

For links to the NH Stone Wall Mapper, as well as a companion website that details the history of stone walls and the use of LiDAR to reveal them, and guidance on how to interact on the map, visit the Stone Wall Project webpage at www.granit.unh.edu/resourcelibrary/specialtopics/stonewalls. Or join the community of stone wall mappers by becoming a member of the NH Stone Wall Mapping Project Facebook group: https://www.facebook.com/groups/NHstonewalls

For more information about the project, contact Rick Chormann at (603) 271-1975 or frederick.chormann@des.nh.gov.