After quite a bit of rain from Tropical Storm Hilary, and I got over 7 inches, here is some information about road closures in unincorporated LA County:

And here is another interactive map, this one from the City of LA:

Also see the US Forest Service page on road closures: https://www.fs.usda.gov/detail/angeles/conditions/?cid=FSBDEV3_027722

Here are some rainfall totals: https://ktla.com/news/california/tropical-storm-hilary-how-much-rain-has-fallen-so-far/