I've heard the
Arson Watch repeater (162.2) is on Saddle Peak, which would make sense since they claim to operate in the Malibu/Lost Hills area; and that it never worked well. I can hear it on my Ventura QTH rooftop antenna, but it doesn't come in very strong (-110dBm-ish). I'd expect a stronger signal from Oat Mountain, which I have visual LOS to, but such a signal strength is within the range I'd expect from Saddle Peak.
The Mt. Wilson repeater (167.9) is deaf, you need a fair bit of power to get into it even if it's full quieting into your receiver. There's a reason why very few people are full quieting into it. The 'justification' for that was that it "keeps the jammers out", but there's no excuse for losing about 30dB of receive performance. Arson Watch repeater does not identify, and Mt. Wilson identifies as WQWE656. I'm not sure if anyone maintains it at all.
The only GMRS repeater on Oat was a short-lived box on 462.550 owned by he-who-shall-not-be-named, but that's been off the air for a little over a year now.