LOCATION: On the left (northeast) bank of the west fork of the San Gabriel River approximately 7 miles above junction of the east and west forks and 0.5 mile downstream from Cogswell Dam. Elevation of zero gage is height 2083.37 feet.
REGULATION: 40.4 square miles regulated by Cogswell Dam, 0.6 square mile unregulated.
CHANNEL: Sand,gravel, and boulders.
CONTROL: Concrete control with low flow notch about 35 feet below the station.
LENGTH OF RECORD: October 1, 1933 to October 1, 1967, and from October 1, 1988 to date.