I'm not 100% what an Earthen dam is, but I would explain the dam as this...The pond sits in-between two big natural hills in the blue ridge mtns and it looks like in the dam end of the pond was man made. It looks like they moved the dirt to make the dam, because on the other side of the dam it drops way down with an overflow pipe sticking out with a lot of water flowing out that pipe that comes from the overflow of the pond. this water coming out of the pipe flows into the large creek that feeds the pond on the shallow end. It's like a large creek flowed in-between these 2 mtns, so they just built up a dirt dam to make a pond.
