Let's not forget about Blythe and San Gorgonio Pass. This route was covered previously in this thread:
https://forums.radioreference.com/g...do-river-santa-monica-10-fwy.html#post1877602
I've updated it somewhat from information I've found tracking calls. This is by no means definitive and could be completely wrong.
Area Office: Area of Responsibility
Blythe: Colorado River to somewhere east of Red Cloud Road
Indio: Somewhere east of Red Cloud Road to Hwy 62 or east from there
San Gorgonio Pass: Hwy 62'ish (the furthest east call I've tracked was just west of Hwy 62) to the Riverside / San Bernardino Counties line
San Bernardino: San Bernardino / Riverside Counties line to Sierra Ave. in Fontana
Rancho Cucamonga: Sierra Ave to San Bernardino / Los Angeles Counties line
Baldwin Park: Los Angeles / San Bernardino Counties line to I-605
East LA: I-605 to around Indiana Ave (City of LA border)
Central LA: Around Indiana (City of LA border) to La Cienega Blvd
West LA: La Cienega to the end of I-10