In this July 2, 1970, file photo, guitarist Jerry Garcia, of the band "The Grateful Dead," left, is joined by Delaney Bramlett, right, in Calgary, Canada, during the legendary "Festival Express," also known as the Transcontinental Pop Festival. 
Recollections of the concert have resurfaced in recent years, with some saying they remember a concert being planned, but it being canceled. Arnold writes on his blog that even a Grateful Dead manager remembered the show to have happened. 
"Various student memories arise, as they always do with the Dead, like that the Dead's equipment truck was driving by and they saw the Clam Jam going on and decided to just play," said Arnold. "Many colleges and town(s) have these stories, almost all, but not quite all, are not true."
Arnold notes that Rick Adams, the drummer of Goodhill, a band that was set to perform at the show, remembered the show being cancelled. 
"Because the Fairfield show was on every list through 2010, until I poked a hole in it, everyone assumes it happened, when it fact it appears it did not," added Arnold. Photo: Ron "Sunshine" Mastrion, AP