GILLETTE - The number of oil and gas drilling rigs in the state climbed to 106 at the end of April, the highest number since 1985, according to the Wyoming Oil and Gas Conservation Commission.

Wyoming's average 96 rigs for the four-month period marks a 32 percent increase over the same period a year ago.

"Demand is high. How long it will last, I don't know," said Patrick Hladky of Gillette-based Cyclone Drilling.

Though Hladky remains somewhat cautious, he's adding two more rigs to his fleet this year. That's in addition to the five that Cyclone added last year.

"I don't think it's slowing down anytime soon," Hladky said.

While deep-well drilling drives the state's large rig count, drilling in the shallower coal-bed methane fields is actually down 18 percent from a year ago. So far, the CBM industry has averaged 42 rigs, compared with 51 rigs in 2005.

Drilling permits industry-wide are down 21 percent, said Likwartz, and some in the industry aren't sure if permit writers can keep up with demand to drill. Through the end of April, the state issued 3,200 drilling permits, compared with 4,050 a year ago.

Drilling is up nationwide and particularly in the Rockies, where the rig count spiked 26 percent during the first four months of the year, according to the Oil and Gas Conservation Commission.