View of falsework during construction of the main arch of the Fourth Street Viaduct over the Los Angeles River, [s.d.]

A concrete pillar can be seen at right. A concrete arch runs from the base of the column at right to center.

Wooden scaffolding supports the arch, and more scaffolding can be seen on top of the arch at right. Several men can be seen on top of the bridge at left, and shallow water can be seen in the river in the foreground at center.