San Francisco Golf Club's original routing was done mostly by a trio of club members, who first staked out the course in 1918. A.W. Tillinghast remodeled the course in 1923, establishing its signature greens and bunkering. He also added the par-3 seventh, called the "Duel Hole," because its location marks the spot of the last legal duel in America. Three holes were replaced in 1950 in anticipation of a street widening project that never happened. In 2006, the original holes were re-established by Tom Doak and his then-associate Jim Urbina.