I have some uncertainty about whether NRPS played with the GD during the handful of January 1971 shows. The New Riders' official tour history from 1971 has listed these shows:
1/21/71, Freeborn Hall, UC Davis, Davis, CA
1/22/71, Lane Community College, Eugene, OR
"1/25/71", Seattle Center Coliseum, Seattle, WA (should be 1/24/71)
Rob Bleetstein, the NRPS archivist, told me where the listings came from, and while I don't recall the specifics I think it was just assumed that the NRPS were at these shows. I have my doubts, for two main reasons.
First, the dog don't bark in any documentary evidence that I can find. I'll keep looking.
Second, NRPS were at Wally Heider's on 1/18-20/71, based on documents I have seen. I'll bet they had to stay home and work on the album while Jerry and the boys took off for a few days.