Thanks guys.
It appears there were 11 races for the T/A series in 1971.
5-8-71 Lime Rock, CN
5-31-71 “Bryar” Louden, NH
6-6-71 “Mid-Ohio; Mansfield, OH
6-20 “Players” Edmonton, Alberta Canada
7-4-71 Donnybrooke, MN
7-18-71 “Road America” Elkhart Lake, WI
8-1-71 St. Jovite, Quebec Canada
8-15-71 Watkins Glen, NY
9-6-71 Irish Hill, MI (MIS)
9-19-71 Kent Washington
10-3-71 “Mission Bell” Riverside, CA
This list helps limit the possibilities.
The building in the Can-Am photo Mike posted from Mid-Ohio looks very similar to the T/A photo.