He was a poor mountaineer/
Barely kept his family fed

Jed is preliterate man, barely holding on to life in a subsistence environment. He is poor, free from the effects of economies of scale and linguistic abstraction, lives in a context of complete presence

One day he was shooting at some food/
When up from the ground came-a bubbling crude.

He has mastered simple tools, note he is SHOOTING for FOOD, not tilling, not digging for it, its accidental. This transformative substance arises by accident while he attempts to stave entropy

First thing you know old Jed's a millionaire/
Kinfolk said 'Jed move away from there'

Money is the first thing that industrial man gains awareness of and immediately his primitive family members cast him out of the familiar context of subsistence foraging into "the world"

California is the place you ought to be.

Manifest destiny, very simple, the creation of the frontier, the first contact with the neverending ray of progress enabled by the vast EROEI given seemingly from heaven

Swimming pools/
Movie stars

The selling points of this new life, the things which are mentioned sensually and seductively are themselves simulations of ideal forms which we achieve through industrialization (swimming pools) and electronic media (movie stars)

Lastly, what is a seemingly innocent physical gag, granny's arms growing weary from having goodbye, symbolizes the spiritual exhaustion which accompanies the end of industrial society. A woman, the birthing figure, who remembers the old ways is exhausted by modern social rituals

She switches hands back and forth. Symbolic of the indecision that arises from technologically induced self awareness. She years for the past, but reaps all the benefits of the future. Be careful what you wish for...