Congratulations to Brian McCarthy, Jim Waechtler, blh, Frank and Scott for correctly identifying last week's mystery 1940s aerial as the Long Island Motor Parkway on the border of Bethpage State Park in Old Bethpage.
A close-up view of the Motor Parkway. The golf course behind it is now the "Yellow Course" of Bethpage State Park.
A close-up of the clubhouse.
As noted by eagle-eye "blh", a sporting event was being held near the clubhouse, likely a polo match.
A matching Google map view of the mystery photo. A trace of the Motor Parkway curve can still be seen.
The curve in the mystery photo is in place today adjacent to the new section of the Bethpage Bikeway.