My guess it would be the ski industry. I hear most resorts have not been able to open due to lack of snow.
That’s probably the best guess...
Some of the mountain ski resorts have their own weather events, while the surrounding areas can be blue sky for as far as the eye can see. Mammoth Lakes/Mammoth Mountains, is but 30 minutes away by air from the Fresno Airport.
Or an agricultural purpose?
The San Joaquin Valley is a major (world-ranked) food crop source.