The soaring value of California’s nut crops is attracting a new breed of thieves who have been making off with the pricey commodities by the truckload.

This harvest season in the Central Valley, thieves cut through a fence and hauled off $400,000 in walnuts. And $100,000 in almonds was stolen by a driver with a fake license. And $100,000 in pistachios was taken by a big-rig driver who left a farm without filling out any paperwork.

Investigators suspect low-level organized crime may have a hand in some cases, while some pilfered nuts are ending up in Los Angeles for resale at farmers markets or disappearing into the black market.

Domestic demand for specialty foods and an expanding Asian market for them have prompted a nut-orchard boom in the state’s agricultural heartland. Such heists have become so common that an industry task force recently formed to devise ways to thwart thieves.

“The Wild West is alive and well in certain aspects,” said Danielle Oliver of the California Farm Bureau Federation. “There’s always someone out there trying to make a quick dollar on somebody else’s hard work.”

Amid the nut boom, farmers have torn out vineyards and other crops to plant nut trees to keep up with demand. Real estate firms, retirement funds and insurance companies have taken note by adding almond, walnut and pistachio land to diversify their portfolios.

As the nation’s top nut producer, the state grows more almonds and pistachios than any other country. Only China produces more walnuts, which have nearly tripled in price in the past five years to about $2 a pound, according to the California Walnut Board.

The U.S. Agriculture Department reported that through 2012 the state’s almond crop was valued at $5 billion per year, pistachios were over $1 billion and walnuts were over $1.5 billion.

“Right now, everybody wants to be a nut grower because it’s kind of like the gold rush of the 1850s,” said Ripon almond farmer Kevin Fondse of Fondse Brothers.

“Everybody wants the gold.”