The Crocker era ended in 1922 when the City of San Francisco purchased the Glen Canyon Park and Recreation site. At present, O'Shaughnessy Boulevard defines the western perimeter of Glen Canyon Park. In conjunction with an extension of Bosworth Street, the Boulevard was built in 1935 using roadcuts and filled slopes on the canyon's steep slopes. It was named after Michael O'Shaughnessy, who was for many years the Chief Engineer of the City. The recreation center at the south end of the park was built by the Works Progress Administration in 1937.