Original 1st printing (Scoop Printing credit/no "Ticketron" imprint) 16&1/4 x 22&1/2" concert poster for "Summer Jam", an all-day show featuring the Allman Brothers Band, the Band and the Grateful Dead appearing together at Watkins Glen Grand Prix Circuit (Racecouse) in Watkins Glen, NY on 7/28/1973 (along with a special "soundcheck" on 7/27*).
Design by Sokoloff/Saban/Mahn, image is featured in the Art of Rock book on page 406 (plate 4.231).
Medium-thick glossy-coated index stock poster is in very good to excellent (B/B+ to B+) condition; a series of ultra-tiny light "pin-prick" surface stains ("foxing") scattered around the outer margins, a set of semi-pronounced vertical stress bends (each about 1&1/2-2") at various points from the top center to the bottom center margin (presumably from a too-tight rubber band), plus a couple of very thin horizontal bends running along the bottom margin, a trace of toning and one or two stray handling dings, otherwise fine.
A great-looking ORIGINAL example of this classic early-'70's GD/Band/ABB poster from one of the most legendary concerts in Grateful Dead history. This image has been reprinted, but the actual real-deal firsts have been harder to come by as of late. Listen to a great-sounding recording of the 7/27 pre-show "soundcheck" here;