North of Los Angeles and Castaic, Piru Creek is well known for trout fly fishing. One of the best sections is the catch-and-release area below Pyramid Dam. This section runs for three miles down to Frenchmans Flat. There is relatively easy access at Frenchmans Flat on Piru Creek where the rainbow trout is stocked in the late summer.
To reach the Frenchmans Flat fly fishing access for Piru Creek from Castaic, head north on US5 for 7.5 miles to Templin Highway. Follow Old SR99 west and then north for five miles to Frenchmans Flat on Piru Creek.
Overall, Piru Creek is the 1st most popular fly fishing river of all 17 fly fishing spots in California.