BIG SKY, Mont. — The West once symbolized a land of limitless resources and potential.

Now it appears Americans are exhausting one of the region's most sought-after commodities — natural gas.

At present consumption rates, the supply of natural gas in the United States will be depleted in 50 years, according to Rebecca Watson, assistant secretary of land and minerals management for the U.S. Interior Department.

"Over the next 20 years, U.S. natural gas consumption is projected to grow by more than 50 percent," Watson said, "but our supply, if it grows at the same rate it has over the last 10 years, will grow by only 14 percent."

Watson's assessment on Sunday, before the Western Governors Association's annual meeting, cast yet another shadow over an industry where volatile price spikes and uncertainty are becoming routine.

Don't expect a return to low prices that characterized much of the 1990s, said Robert Card, under secretary for energy, science and environment at the U.S. Department of Energy.

Simply put, start praying for a warm winter to avoid another price spike that squeezed consumers during the winter of 2000-01. In Utah, Questar Gas customers will see their heating bills rise nearly 20 percent over last winter. The high cost of natural gas also is pushing Utah Power to request a $125 million increase, the second-largest rate hike in more than a decade.

Part of the blame reaches back more than a decade ago when the federal government enacted policies encouraging gas consumption while discouraging production, Card said.

In fact, the burning of natural gas was once off-limits to electrical power plants. But as environmental concerns mounted over the emissions of coal-fired plants, natural gas appeared the easy alternative.

Today, 95 percent of all new power plants built are fired by natural gas. Roughly 28 percent of the nation's electricity is produced by natural gas.

"As we do in all things, we get a little over-enthusiastic," Watson said. "No one thought forward enough to understand that natural gas has to be produced and we have to have some lead time. We have to have pipelines to transmit it."

Alaska Gov. Frank Murkowski said if the proposed $20 billion trans-Alaskan natural gas pipeline — expected to run from Alaska to the lower 48 states — does not materialize, imported liquefied natural gas, from the Middle East or Indonesia, will likely fill the rising gap.

That would not only cost future U.S. jobs but would translate into ever higher natural gas costs for consumers, Murkowski said. "It means that we export our dollars overseas," he said.

Murkowski, who also favors oil exploration in the Arctic National Wildlife Reserve, said the nation is being held hostage by the Middle East.

"America and the world moves on oil," he said. "Every time OPEC has a meeting, we cough. We cough deep as a consequence of what the OPEC dictate might be. We have to be able to offset that."

Ralph Klein, premier of Alberta, Canada, said everyone wants energy, but no one likes how it is developed.

"No matter how we try and develop clean-coal technology, coal is still deemed to be a dirty thing," Klein said. "So the environmental community says, 'No, you can't use coal.' Try and build a dam, they will go absolutely berserk. Then they say wind power is the way. But now we see with the development of wind farms, people are saying now we are getting visual pollution …. It doesn't matter how you attempt to generate electricity, there is going to be a downside."

Expect to hear more conservation messages in the coming months. In the next one to two years, it is critical for states to look vigorously for alternatives to natural gas, Card said.

"For the first time I remember, the natural gas producer industry is calling for conservation," he said. "You know when that industry is calling for that we've got a serious problem."