High Quality Content by WIKIPEDIA articles! The 1966 U.S. Open was the 66th U.S. Open. The golf tournament was held June 16–20, 1966, at Olympic Club in San Francisco, California. Billy Casper staged one of the greatest comebacks in history by erasing a seven-stroke deficit on the final nine holes to tie Arnold Palmer, then prevailed in an 18-hole playoff for his second U.S. Open title.