Mark West Creek is a 29.9-mile-long (48.1 km) stream that rises in the Mayacamas Mountains of Sonoma County, California, United States. Tributaries of Mark West Creek include and , both of which originate in the same mountain range. Discharge waters of Mark West Creek reach the Russian River after a confluence with the Laguna de Santa Rosa. The Community Clean Water Institute has developed a program for monitoring pollutants in Mark West Creek. The four-mile stretch of Mark West Creek from Mark West Lodge to Mark West Creek Road is a challenging class III-V whitewater kayaking run.