For Mt Wilson – I like hitting Golden Road Brewing. It’s not really close to the trailhead, but it is right off I-5 near Griffith Park, so for a lot of people (me included) it’s “on the way home.” Good menu, too.
For Baldy & Cucamonga – check out Dale Bros Brewery. They don’t have a kitchen but they have rotating food trucks (posted on their calendar).
For San Bernardino and San Gorgonio – I like Hangar 24 Brewery in Redlands. Same as above, they don’t have a kitchen but they have food trucks.
And for San Jacinto via Idyllwild, try Arriba’s Mexican Restaurant. They have a great deck out back. Apparently they don’t have a website but it’s not hard to find.
Happy Trails!