Loretta, I believe it is from a brown shale used as the road aggregate. I remember going down a road in Virginia about 10 years ago, where the road changed color every mile for about 10 miles. Quite a rainbow. Turns out they were testing different aggregates for durability and tje stone had different colors. Red, brown, green, gray, many shades.

George

Thanks George,
That's interesting. I'm going to look into that.
Loretta