I don't think those are airstrips. Looks like they have big radio antennas on them. I know there are some microwave telcom relays in the area (near Gorman), though those are much too big for microwave.
I'm planning a flight down there tomorrow, past GMN, and that isn't too far out of they way. Maybe I'll peek if it isn't too windy. Forecast is for strong northerly wind, so a south slope of a 6000 foot mountain may not be a good place.
There are A TON of uncharted private strips all over rural California. Some of them quite nice.