So I found what seems like a reliable muskrat site in Oxnard. It is the Ormand Beach wetlands, which isn’t very wet right now but does have a canal right by the parking lot which should produce muskrat sightings with some effort. I have gone twice at about the last 2 hours of daylight and both times saw 2 different muskrats. The guy who is the ranger for the area is really cool too. Overall the site is not beautifully well preserved but having muskrat so close to Los Angeles is really awesome. The ranger also informed me that long tailed weasel can sometimes be seen. The reeds can make viewing difficult in spots but I think with some perseverance this is an excellent place to look for muskrat.