US Crude Oil Production, 1900-2010, for major producing states and the Federal Offshore GOM:

Data from "Oil Prices, Exhaustible Resources, and Economic Growth" by James D. Hamilton, h/t TOD member aws.classifieds.

Note how LA and the GOM area sharply declined right before TX, along with a passel of minor states, some of which I haven't included here for clarity's sake. CA also had the second of three local peaks on its long bumpy plateau. It seems like these would be strong warning signs that the nation as a whole was in trouble; albeit, one can see how Hubbert's forecasts must have seemed unlikely before the peak, given the decades of ramping up that had taken place.

That bumpy plateau is intriguing. CA oil is very heavy, hence slow to extract, hence gentle in its decline. CERA would apply to the world as a whole with econometric factors at play, I'd imagine; there wasn't money to cushion TX decline so it was fairly steep; or at least I think that's the idea. Price shocks don't look to have slowed the fall there one bit.