Last night, the LA Times' Louis Sahagun reported a piece of data dynamite the Energy Information Administration plans to detonate under California next month: There now appears to be just 600 million barrels of recoverable tight oil in the state's vast Monterey shale play — a downward revision of 96% from the agency's 2011 estimate.

The revision seems to have been predicted in a report from geoscientist J. David Hughes, best known for his work on Canadian oil formations, and published by the Post Carbon Institute in December. Hughes warned that Monterey's geology, while superficially similar to marquee tight oil plays in Texas and North Dakota, actually contains an enormous number of irregularities that would make it difficult to ever successfully extract the resources.

"The target strata in the Bakken and the Eagle Ford plays are less than a few hundred feet inthickness and are flat-lying to gently dipping," the report said. "The shale deposits of the Monterey are much thicker and much more complex, with target strata up to 2,000 or more feet in thickness, and atdepths that can range from surface outcrops to more than 18,000 feet within a span of fortymiles or less."

The EIA did not respond to requests for comment.

BI had previously talked with experts who said there were so many unknowns about the Monterey that it wasn't really on anyone's radars as a potential new chapter in the Great American Shale Boom. "It is not a focus right now," ITG's David Howard told us in December. "The market has moved away from really paying attention California unconventional and I follow the market."

So, it's debatable whether it can reasonably be called "a blow to the nation's oil future," as the LAT's Sahagun put it, since no one was really factoring it into that future in the first place.

But it certainly makes things extremely awkward for California.

The state had pinned its hopes on a March 2013 USC study that argued tapping the Monterey could create up to 2.8 million jobs by 2020 and add up to $25 billion to state and local tax revenue. "Californians drive 332 billion, that's billion miles a year, fed almost entirely by oil products, so we have got to start hammering at the demand, as well as the sources of fossil fuel," California Governor Jerry Brown told CNN Sunday.

In September 2013, Brown — often labeled as having a thumb as green as Shrek's — signed into law a bill that allowed the small-scale fracking that already occurs in to continue, with a view toward one day tapping what was thought to be Monterey's vast and accessible deposits.

Brown's office had no comment Wednesday.

The good news is that outside California, the findings may not mean all that much. The most recent revisions to the country's marquee shale plays like the Bakken have actually gone upward. Reached by BI Wednesday, Hughes said his analysis of other mega American shale plays don't differ greatly with the EIA's.

"So far I don't see any kind of radical downgrade that might occur," he said.

But for the Golden State, the second coming of a black gold rush looks to have been a mirage all along.