This subject was crowd-sourced on 11 May 2018 via the Granville-Tolland Community Forum (Facebook). The following information was collected:

1. Location of High Rock: On the south side of Bad Luck Mountain, behind the properties on the north side of Main Road going up Granville Hill. Also described as, "Behind the telephone building on Bad Luck Mountain."
2. Several people recall being told that Calvin Coolidge attended clam bakes there.
3. See "Comments" below for additional location information.
4. Timeframe: A few photos indicate "1930 +/-".]]>