It runs from the Conejo Hills of Newbury Park, crosses horizontally Casa Conejo, before entering Thousand Oaks and Wildwood Regional Park. It originates in the Conejo Hills and streams into Hill Canyon and further into the Santa Rosa Valley, where it merges with Arroyo Santa Rosa and becomes Conejo Creek. Conejo Creek drains through the Pleasant Valley Basin, joins Calleguas Creek and enters into the Pacific Ocean by its estuary at Mugu Lagoon at the north end of the Santa Monica Mountains. Its northern border is made up by the Santa Susana Mountains, South Mountain and the Oak Ridge Mountains. Its southern boundary is compromised by the Santa Monica Mountains to the southwest and the Simi Hills to the southeast.