Soaring oil prices have drawn increasingly professional criminals into the heart of U.S. shale country, where oil theft is now often carried out in targeted, organized heists rather than as opportunistic petty crime.

West Texas Intermediate crude is up 60% so far this year, reflecting the run-up in prices since the war began. Fuel prices have climbed even further as global refining capacity has fallen amid the conflicts in the Middle East and between Russia and Ukraine. With U.S. oil lately hovering around $100 a barrel, the payoff from stealing crude has become hard for criminals to resist, with every diverted barrel now commanding far more than it did at the start of the year.

The problem has grown prevalent enough that the Federal Reserve Bank of Dallas now asks about it in its quarterly energy surveys, a recurring barometer of conditions across the region’s energy industry. According to the latest survey, nearly half of firms focused primarily on the Permian Basin said their operations have been impacted by theft in the oil fields. By contrast, 86% of firms operating mostly outside the Permian said they had not been affected. With the survey running quarterly, future editions will give operators and regulators a regular read on how the problem evolves.

The Permian Basin, stretching across West Texas and southeastern New Mexico, is the heart of the U.S. oil patch and the epicenter of the shale revolution that transformed the country into an energy superpower, and it ranks among the most prolific oil-producing regions in the world. The region is dotted with drilling rigs, pipelines, trucks, tank batteries, and other essential infrastructure spread across vast, sparsely populated terrain, making it a target-rich environment.

Among executives who reported being impacted by theft, 32% said it had increased slightly over the last 12 months, 47% said it had remained the same, and 22% said it had decreased slightly or significantly, the Dallas Fed found. Nearly half of oil executives—47%—said the most common form of theft was targeted and organized, while 42% described it as opportunistic petty theft. Even so, losses were relatively minimal, with 84% saying the financial impact of the theft was low.

A year ago, the Dallas Fed asked a slightly different set of questions about what exactly was being stolen. In that survey, 61% of respondents said crude oil; 58% cited piping, valves, and wiring; 39% said equipment; 27% said tools; and 12% reported construction equipment and vehicles.

The thieves are not always lone operators. In August, executives from a wastewater disposal company were charged with felony oil theft, money laundering, and organized crime. The charges came out of Operation Black Market Basin, an investigation that resulted in the seizure of more than $12 million in petroleum products, vehicles, cash, and other assets, according to the Texas Railroad Commission, which—despite its name—regulates the state’s oil and gas industry. The commission added that the probe involved petroleum allegedly acquired and sold across Texas, New Mexico, and Oklahoma, a multistate footprint consistent with the organized patterns executives describe in the survey.

In April, federal prosecutors announced charges in a large-scale oil theft conspiracy in the Permian Basin to transport stolen crude oil across the New Mexico-Texas border for resale—the kind of interstate movement that brought that case into federal court.

Local officials say the scale of the problem is substantial. Howard County Sheriff Stan Parker told Texas Public Radio in May that his county, which sits near the Midland-Odessa oil hub, sees “probably over 1,000, 1,500 barrels of oil reported stolen every month.”

“Our problem is we don’t know who’s supposed to be there and who’s not,” Parker said. “If I pulled up on a tank battery right now, I don’t know if you can be there or you’re not. I don’t know if you’re drawing water off of it. I don’t know if you’re pulling oil. It’s got very complicated.”

This story was originally featured on Fortune.