Monte,
It was interesting in that it was a pretty sterile area compared to what one might expect. We did find a few noisy areas that we would encounter in most any ghost town, but a large portion of the site wasn't very noisy. Guessing they didn't have a lot of steel lying around in 1870 as this is a remote area, and there was likely a lot of wood used for structures, or canvas as i found a small handful of the canvas grommets. You do find square nails, but not in huge quantities. Some broken down tin or thin steel plate. The larger coil was useful in this environment, and i'm not a big fan of the stock sport coil as its a little heavy to swing all day and not super well balanced. The spider coil was working nicely on my V3i, and the MF allowed to frequently avoid the tin/deep iron and classify the old rimfire shell casing and pull tabs very well....as i dug dozens to see the repeatability.
I think that you could have found what i found with a Harbor Freight detector. Just was the luck of getting a coil over them as they were shallow and not masked. Now, obviously there is more out there, but i don't think a lot more. We really covered ground and it was reasonably clear that targets were either sparse or the ground had been reworked over the 100 years the areas has seen activity.
Like you, i imagine what it might be like if some of our sites burned off, but having a large fire within 3-4 miles of our house in the last week leaves me with the realization that its unlikely we will ever see a controlled/non destructive cleanup in my lifetime. I do know that our local parks need the invasive ivy and the poison oak gone as it really makes it almost impossible to detect. That ivy is awful stuff and i know the city wishes it was eradicated. They send in work crews to clear it, and within 3-5 years its a jungle again.
But, i continue to be thankful for the opportunities to hunt and the fascinating finds made and shared. Its a hoot!
Zincoln