Jan. 5--Subzero temperatures from Billings to Minot, N.D., have sparked a run on high-grade diesel fuel, with some rural areas going without.

Demand for No. 1 diesel, the kind that still flows at minus-20 degrees and cooler, surged in December as extremely cold temperatures socked the region for two weeks beginning in mid-month. Trucks caught with lower fuel grades in their tanks or mixtures of No. 1 and No. 2 diesel stalled as their diesel congealed in the cold temperatures.

Green-handled fuel nozzles at gas stations where No. 1 diesel supplies dried up were hooded.

"The Cenex around here has been selling a 50-50 blend, and it works great until it's 20 below. Then you're stuck on the side of the road," said Sid Waller, of Community Oil Co. in Reserve.

There was a run on high-grade diesel at Community Oil in late December after word got out that the small company had several hundred gallons.

In a strange twist, it was truck drivers hauling raw crude from the oil fields along the Montana-North Dakota border who became Waller's clients.

Community Oil is roughly 18 miles from North Dakota and 30 miles from Canada, areas where oil drilling is booming but refined product is lacking. With roughly a million gallons sold each year, Community is one of the smaller fuel operations in the region.

Freight haulers, with special heating systems to keep fuel pourable, have fared better. But finding No. 1 diesel on the road has been difficult, said Frank Molodecki, of Billings-based Diversified Transfer and Storage, or DTS Billings.

DTS has a full-time fuel purchasing agent, who tells Molodecki that No. 1 diesel is hard to come by even into Colorado. Haulers can get by on a blend of No. 1 and other fuels in their trucks, but their refrigerated trailers need fuel that holds up at colder temperatures.

Weather has the region thirsty for No. 1 diesel, but so do bargain-hunting farmers, nervous about the return of last summer's $4-per-gallon price. Cenex Harvest States, which has a Laurel refinery, is seeing demand for diesel jump 40 percent overall in the 25 states it serves, said Mike Derickson, CHS manager of refined fuels, marketing and operations. The increase is much higher in areas bit by bitter cold.

"The demand for No. 1 has been 180 to 200 percent of last year's demand, and that's what we've delivered," Derickson said.

Diesel production is an ongoing challenge for refineries because it's only a fraction of the fuel produced when oil is refined. Typically, the refining process creates 2 gallons of gasoline for every gallon of diesel.