From Dave Brigham:
In 1870, somebody discovered a yellow ochre deposit in Lexington, Massachusetts. Well, I'm sure other folks (read: Native Americans) knew about it before then, but in 1870 a person or persons stumbled across it and formed the Boston and Lexington Paint Company, which, from what I've read online, was a short-lived venture.
I stumbled across the paint mine, as the conservation area is known, on Google Maps. I didn't know what I was looking for when I hiked through it with my son earlier this summer. We didn't find the mine, although there are remnants of it, according to the town of Lexington web site.
We had a nice hike, saw a deer and searched high and low for whatever a yellow ochre deposit looks like. We came across this old foundation, but I have no idea what the history is behind it.