Mark Donohue

Al Unser (left), Mark Donohue (center) and Bobby Unser chat on pit road before the 1973 Schaefer 500.

Mark Donohue (left) talks with crew members on pit road.

Mario Andretti signs autographs for fans at Pocono Int'l Raceway.
Cars line pit road prior to the start of the third annual USAC Schaefer 500 at Pocono Int'l Raceway.

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