I saw the Greatful Dead three times during this period and this is the only show I remember the precise date. I traveled up from Bloomington with a guy named Dan in a brown Duster. He got as far as the city limits and decided he was too out-of-it to proceed beyond the Indianapolis city limits. I drove the rest of the way to the hall. Once we got inside Market Square, we both went to the restroom and after that we got separated. I did not see him for the entire concert. When the show was over, I found him passed out on the parking lot next to the passenger side door of the brown Duster. This is the kind of weirdness that became rather commonplace for a while when I was in college.
What a long strange trip it's been! I was living in Big Elk Meadows, south of Estes Park, CO when this show was announced. My VW bus was disabled, so I decided to hitchhike to Indianapolis. 30 hours and 26 rides later, I got dropped off right outside Market Square Arena minutes before the show started. You can imagine how stoked I was to actually locate friends from Ohio and get seated before the 1st notes of Bertha. Check out the great recording on archive.org, by Jerry Moore: it's one of my favorite cd's!!