Salisbury Hill — Follow the LiDAR (Part 1)

In last week’s entry on Salisbury Hill, I described how I go about mapping an area that is new to me.

Yesterday I returned to polish that up, along with doing some further looking for remnants of the Hopewell structure on top of the hill.

Now that I had a general feel for the area, it was time to enhance things. Part of that is just to look more closely at the terrain, which might have me adjust the location of where I drew a trail. But I’d also had a chance to do a bit more searching on the internet, where I found an interesting paper on the Hopewell mounds on the hill. I also had a chance to grab LiDAR data for the area and make some maps based upon it.

I thought I’d start out by showing a picture of the whole Newark, Ohio area.

A LiDAR View of the Newark Area

To create it I generated about a hundred main LiDAR tiles, reduced them to a tenth, and then pasted them together. While the Newark Earthworks do show up in LiDAR, they are pretty indistinct at this scale, so I overdrew them in black. I also added the “missing” parts in purple, based upon the Salisbury map. The original is 2400×1600, so you need to click on the image to see it in its full glory.

You can also see how the three rivers (North Fork of the Licking, South Fork of the Licking, and Raccoon Creek) and their valleys come together in a wide, fertile area before heading out east as the full Licking River. No wonder why this place was chosen as a location for the earthworks.

By the way, Salisbury Hill is right near the bottom of the picture, in the middle, directly overlooking the South Fork of the Licking.

In fact, here’s a closer look.

Salisbury Hill

What I had with me this time was the result of finding the following picture.

Romain and Burks Figure 12 Showing the Salisbury Hill Earthworks via LiDAR

It was in LiDAR Assessment of the Newark Earthworks, and gave me a pretty good idea where to look to see if I could find the remains on Salisbury Hill.

Now, you’ll notice that my LiDAR picture of the mound doesn’t show anything the way the paper does. But then again, it’s a fairly gross rendering of the elevations. So I processed the heck out of the data in a way to exaggerate any minute elevation changes, and I too could see the earthworks line. In addition, I created a topo map from the data, and here is the result.

My Annotated Salisbury Hill Topo Map (from LiDAR data)

The darker lines are 100 foot elevations (Salisbury Hill rises to just above 1065 feet above sea level) and the browner lines are every 10 feet of elevation. Just at the top I added a 5 foot line (in blue). There in red is the anomoly, placed precisely atop the appropriate topo line.

What I found interesting, and which was not pointed out in the paper, was how that location was so perfectly described by Salisbury:

Around the level summit of the hill, generally about four rods below its brow is a ditch and low wall . . .. This ditch is nearly circular, yet evidently conforming to the shape of the hill . . . The wall . . . is almost obliterated, having been washed into the ditch by the rains of centuries.

A rod is about 5½ feet, so 4 rods is about 22 feet, which hits that 1040 foot topo line pretty perfectly.

So, what did I see up there?

Well, I did find the anomaly that shows up in LiDAR. That was pretty easy to do, once I knew where to look. Here’s a picture of it.

The Remaining Hint of Earthworks

If you look carefully, you can see how the slope of the hill is interrupted by a bit of flatness. That’s what shows up on LiDAR (after processing the heck out of it!). A camera just isn’t very good (or I’m not a good enough photographer) at showing the subtleties in the terrain that can easily be seen by a trained eye. [And yes, it was a gorgeous day!]

To tell you the truth, it really didn’t look any different than any other trail that one comes across in the woods. But there was one thing that distinguished it from those trails and let me know that it was much older than the rest of the trails.

Younger trails don’t have this growing in the middle of them.

More of the Faint Remains

(For both pictures, click for larger versions.)

Obviously, other remote sensing tools would have to be used (heck, maybe they already have) to confirm that this feature really is the earthworks.

By the way, the north-pointing part of the anomaly is the end of the path (old road) that leads to the top of the hill. It’s pretty obvious that it has obliterated, and probably overlays, any earthworks.

For this second trip for me to Salisbury Hill, I also brought my zoom lens, so here’s a picture shooting across the valley.

Looking Across the Valley (and intervening shopping malls)

That tower is probably 5 or 6 miles away on the other side of the valley. You can also see, however, how things have filled in between the high points. And 2000 years ago, that would have been prairie with the major earthworks in view.

Just as the topo maps show, the top of the hill really is quite flat. Being up there, it’s also rather susceptible to stronger winds, and it has thinner soils for trees to grab hold of. So they sometimes come down.

I just could not resist this shot.

Up a Tree Atop the Hill

One reason is just to remind folks that I do these hikes barefoot, including the bushwhacking around looking for the earthworks. It is just such a much more immersive way to hike. But this is an interesting shot—as the trees came down they got stopped by hitting another tree off to the left that is still holding them up, giving us this leaning tower of trees.

This was not the end of my hike. I not only wanted to explore the earthworks location, I also wanted to explore other parts of the Preserve and add to my official map the trails I hadn’t trekked last time.

I’ll save the rest of the hike for tomorrow’s blog entry.

[Update: Here is Part 2.]