The "On Guppy Pond" Cabin was completed in 1978. The date stamped on the some of the plywood visible in the "basement" indicates 1974 ... so construction may have taken a while! The current "On Guppy Pond" partnership was established in March, 1984. New families have since joined, and all of the original families have sold their interest, but the partnership and "On Guppy Pond" traditions carry on.
For a complete history and photos from "the old days", click link below (password protected):
Complete History of "On Guppy Pond"