Digitizing the Past

Stone walls are a familiar sight across New England. An 1871 survey by the US Department of Agriculture documented 250,000 miles of stone walls in the Northeast United States.

Advancements in LiDAR technology have numerous applications in archaeology. Remote sensing has the potential to detect historical features across large-scale landscapes. It can reveal stone walls or cellar holes "off the beaten path", or those that have decayed and may be obscured by natural debris. LiDAR is particularly useful to detect stone walls in forested landscapes, where features may be obscured beneath the forest canopy.

Stone walls can be used as reference points to locate other historical features, such as cemeteries and property lines. The layout can also illustrate the subdivision of colonial farmsteads.

I used two primary datasets for this project, accessed via the ArcGIS Online Portal:  Rhode Island Shaded Relief (Spring 2022 )  Rhode Island Digital Aerial Photographs (April 2020) 

I also reviewed some historical maps, accessed via the  USGS TopoView Map Locator .

And, as this project began with a personal curiosity, I referenced Points of Interest (POIs) from past explorations of the North Woods using metadata from photos displayed in this StoryMap.

This project involved digitizing point, line, and polygon features representing different historical points of interest (POIs) in the North Woods. First, I had to tailor my data to my study area. I used Clip Raster on the Shaded Relief layer, and Extract by Mask on the Aerial Imagery. This made the data much more manageable. That was the extent of my work in ModelBuilder.

The bulk of the project involved pouring over the Shaded Relief layer to search for stone walls and other POIs. I used Aerial Imagery to verify the presence of stone walls as well. The Slider Tool was a treasured resource for this project. As I progressed, it became easier to recognize POIs based on surrounding features I had digitized.

I bounced back and forth between digitizing different feature layers. Once I had a solid foundation for my stone wall data set, I began adding cellar holes and vernal pools. The process was non-linear, as I often found new features while I was working on another layer. For example, I noticed the agricultural sites while searching for stone walls; later, while viewing the agricultural sites more closely, I was able to recognize additional stone walls.

It also became apparent that the trails in the North Woods are well-established, as several of them are plainly visible in the DEM. I added a .tiff of a trail map in the North Woods to discern whether the features were footpaths or possible property lines.

I also noted features that indicate two of the longer trails are historic roads. I verified this by referencing historic maps, namely, a  1944 Topographic Map from the USGS  which has symbology marking "Unimproved Dirt Roads". In some places, I also noticed shorter segments (off-trail) that resembled possible wheel marks. I added those to the Roads layer, as they merit investigation.

A vernal pool near Flagg Road presents an intriguing study sight. Classes such as Herpetology and Wetland Ecohydrology visit this site to learn about the ecological significance of vernal pools. Vernal pools are ephemeral wetlands, which dry up for part of the year. They play a vital role in the life cycle of certain amphibian species. Wood frogs, American toads, and spring peepers have been documented breeding in this vernal pool.

Cleft granite blocks surrounding the vernal pool indicates that it was modified or created by humans. It may have been used as a watering hole for livestock.

I once found a “coffin nail” in a piece of wood inside this vernal pool, after it had dried up for the season in Summer 2023. Coffin nails are named for their flat sides, as they were hand-hammered by blacksmiths. The nail may have dated to the late 1800s or early 1900s.

I left that nail where I found it, because it's a historic artifact. Someday, someone with more expertise may be able to use it to unravel more of the story of this place.

Granite blocks were split by drilling bore holes at regular intervals, and hammering small metal wedges down into them. Three vertical bore holes are visible on the bottom of this block. They're under an inch in diameter, spaced roughly six to eight inches apart.

You can't help but wonder: what happened here? Why were these blocks placed? Why have they been moved from the position they were originally in? With such large pieces, they must have been re-arranged or removed intentionally. It's possible some of them were re-used elsewhere.

Map: Everts and Richards 1895, Provided by Kris Bovy.

The Underwood Site is a documented farmstead, present on this 1895 map, as well as other historic maps.

A report completed by URI Professor Dr. Bill Turnbaugh in 1976 referenced decaying structures at the site, which may have been remains of homes or farm buildings. Pieces of rubbish are scattered across the site. While it seems like trash, the age of these materials (50 years or more) means that they have  historical value .

Some anthropology classes visit the Underwood Site. Here, several old foundations lie adjacent to a small plot surrounded by stone walls. Inside the plot are daffodils and evenly spaced trees/vines, indicating that it may have been an orchard or a garden. Bloodroot, a rare native plant with medicinal properties, grows among the daffodils. Its presence with an ornamental non-native plant may be a sign that it was cultivated intentionally.

In the image, an ash tree large enough for a person to stand inside grows in the heart of the Underwood Site. With decay in the trunk, it may not be alive much longer. An ash tree takes decades to reach such a size; it may even be more than a century old. It was certainly standing when people last lived here.

I found this section of trail to be especially compelling on personal explorations in the North Woods. The green line represents a historic dirt road (now a trail known as Driftway 1). It runs past several unique historical masonry features.

A drainage ditch, in some places reinforced with stones, runs parallel to this section of the historic road. Here, you can see a stone culvert was constructed where the drainage ditch crosses underneath the road.

In some places, it appears that you can see cobbles in the roadway as well. Were they placed intentionally, as reinforcement? Or are they simply a result of erosion?