I haven't thought about this in awhile but apparently Estimated Prophet is about folks that move to The Promise Land (California) and have a hard time handling their LSD.
Don't worry about me, Lord.
From a 1981 interview with Bob and Jerry Here's all 95 minutes
This aired on or about September 11-13, 1981 or the first time the Dead played a weekend at the Greek. The radio show was called Interview. I'm sure Light into Ashes or Corry will tell me more.
Blair Jackson's Piece on Estimated