How long was the 1906 rupture?

The following figure shows the extent of the 1906 rupture seen at the surface. (Slip on offshore segments of the San Andreas fault north and south of Shelter Cove is inferred from comparisons of geodetic observations made before and after 1906).

The total length is 296 miles (477 kilometers). For comparison, the 1989 Loma Prieta earthquake had a rupture length of about 25 miles (40 km).

San Francisco City Hall after the 1906 Earthquake