Joe:
Sorry, but Bob is just plain wrong, despite him having resided in Almonesson since 1950. Here is a post card view of the mill and the bridge over the dam and it exactly matches these structures in your photograph:
View attachment 5110
The only difference is the tree on the lake bank is gone in your photograph. Because this mill building was not erected until the late 1860s, it has an entirely different massing and fenestration pattern than mills constructed earlier in the Camden and Gloucester county area.
In found I could not paste the image into the comment box on your website, Joe, so feel free to clip and paste the image and the text into your website.
Best regards,
Jerseyman