http://books.google.com/books?id=eml9U2RZArQC&printsec=frontcover&dq=7th+Rhode+Island+regiment&hl=en&sa=X&ei=2zDTUcW2K-rw0gHE8oCgCw&ved=0CC0Q6AEwAA#v=onepage&q=%20Fort%20Mahone&f=false

See page .p.280 for site of Picket Post {according to Frassanito this was actaully taken in front of Ft Mahone
second picture of site in 1892

Any modern day versions?