A couple of things to follow up on that Vicksburg Post article about when David and three of his friends carved "Remember Duane Allman" into the side of a Mississippi road cut.
A scan of the Vicksburg Post of October 15, 2007 (it's the article I had previously linked to, but I scanned it so you can see how big it was on the front page of the Post).
A detail from the photo the Post printed showing David Reid standing next to the 6 foot high carved letters.
A scan of the Rolling Stone "Random Notes" item from April 11, 1974 that first brought the carving to national attention. This photo has appeared in several of the Rolling Stone's "best of" collections over the years. (And now, I suppose, it's in the new Rolling Stone Cover to Cover: The First 40 Years three DVD set.)
Update: Don Antoine loaned me some slides of the carving in progress to scan in and I did so.