Athens, Ohio, show?

[Van Runkle]

An acquaintance of mine told me the other day that when he was attending Ohio University in Athens, the Dead showed up on campus and spent some time, then played a free show outside.  He said it was in May of 1968 or 1969 and the weather was nice.  The only listing in Deadlists for Athens, Ohio, is for 11-23-68, which is within that general time frame, and it was supposedly a free show, but it is listed as an indoor show (as it pretty much would have to be, that time of year).   Any thoughts, or is this person's recollection flawed?