<Tr> <Td> - min </Td> <Td> 2 cu ft / s (0.06 m / s) </Td> </Tr> <Tr> <Td_colspan="2"> Map of the Los Angeles River watershed </Td> </Tr> <P> The Los Angeles River (L.A. River) starts in the Simi Hills and Santa Susana Mountains and flows through Los Angeles County, California, from Canoga Park in the western end of the San Fernando Valley, nearly 48 miles (77 km) southeast to its mouth in Long Beach . Several tributaries join the once free - flowing and frequently flooding river, forming alluvial flood plains along its banks . It now flows through a concrete channel on a fixed course, which was built after a series of devastating floods in the early 20th century . </P> <P> Environmental groups, park advocates and city council members support the removal of concrete and the restoration of natural vegetation and wildlife . Portions of the river now have earthen bottoms and restored habitat . There are also plans for a series of parks along the river's city frontage in Los Angeles . The Los Angeles River also flows through several Los Angeles County communities and has been featured in many Hollywood films . </P>

Where does the los angeles river start and end
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