The first Rainbow Roundup was held in 1972 - in the basement of the old St. Bernard Church in Little Current.

Ben S. of Wikwemikong contacted Charlie C. in Philadelphia, who promptly gathered a group of 18-20 people to travel up to Manitoulin Island. The Philadelphia group included Bill R., Art A., Joan A., and Charlie C. This first Roundup was attended by about 40 people in total. Mary R., of Birch Island, was 2 years sober when she chaired one of the panels; Rosemary and Anne B. also chaired a panel at that time.

The Rainbow Roundup has been held every year since. Today, the venue has moved to the NEMI Recreation Center in Little Current to accommodate the  over 250 attendees - and the event still includes an annual delegation from Philadelphia.