The objectives of this study were to determine: (1) the existence of a steelhead resource; (2) life history characteristics and distribution of steelhead in the system; (3) the status of steelhead habitat in the lower Santa Clara River drainage; and (4) streamflow requirements for steelhead in the lower Santa Clara River including recommendations for a streamflow regime based on these requirements. This report presents results of a 2-year field study to verify and describe steelhead resources within the Santa Clara River system, and it presents specific actions that should be taken to protect these resources.