This paper reports briefly on the runoff‐characteristics of the Santa Ynez River in Santa Barbara County, California, following the excessive rainfall in the winter of 1940–41; also, it contrasts these conditions of 1940–41 with earlier years of less rainfall. The data for this report were compiled in connection with an investigation of the water‐resources of Santa Barbara County which is being conducted by the United States Geological Survey in cooperation with the County of Santa Barbara.