Much of the Ventura River's route is contained by the steeply sloped sides of the narrow Ventura Valley, Rincon Consultants, Inc. (June 2014 "Olivas Park Drive Extension Project Final Environmental Impact Report SCH # 1995081004" City of Ventura with its final 0.7 miles through the broader Ventura River estuary, which extends from where it crosses under a 101 Freeway bridge through to the Pacific Ocean.