For generations the Mormon farmers here have worked this dry, desolate plateau in almost total isolation. Virtually untouched by the "gentile" industrial society, they have preserved the simple, self-sufficient life of their pioneer forefathers.

Now, all that may be changing as men representing distant, energy-hungry California utilities seek for the third time to build in the vast, wild land of southern Utah a mamoth coal-fired power plant. At 3,000 megawatts one of the largest such plants ever proposed in this country, the current plan, called the Intermountain Power Project (IPP), may be the only thing that can prevent widespread blackouts and brownouts in Los Angeles over the next decades, California energy officials insist.

Occupying more than 9,000 now-open acres, the plant, which appears to finally have found a site to call home, will scatter the pristine condition of the arid region. Two giant, 750-foot stacks will loom in front of the blue mountains surrounding the site, emitting smoke that will be seen for miles through what is now completely clean, dry air.

But to the people here, the fate of the local environment seems to be of only minimal concern. More important to these work-oriented. More important to these work-oriented people is whether IPP, in pursuit of industrialized wealth, will forever undermine the agricultural foundation of their well ordered, traditional society. Scheduled to go on line in the mid-1980s. IPP is expected to drain from this already dry land up to 45,000 acre-feet of water and return at least 15,000 now-cultivated acres to the original sagebrush, in exchange for 550 permanent, full-time jobs in this depressed region.

To men like Garold Moodv. a dairy farmer here for over a half century, replacing farms with industry meant to feed the insatiable needs of Los Angeles makes little sense. "It looks kind of odd to me," Moody said. "We're supposed to be the backbone of this country but everyone seems to be dissatisfied. Everyone wants more - more taxes, more energy, more money to spend. I don't think we can keep it up and still provide food for everyone at the table."

Most of Moody's fellow Mormon farmers, however, seem to favor IPP, claiming that agriculture is already on the decline here and industry provides the only way to make up the economic slack. Empty barns, deserted farmhouses and depopulated towns are spread across this high, rolling countryside: Fully 15 percent of the area's farmland has been deserted over the last 10 years.

After World War II, Lynndyl was a thriving cattle town of 800 population: today it is a tiny, shrinking hamlet with less than 100 residents.

"We've had a lot of rough years here," said Phil Nielson, a local cattle-man and realtor, whose descendants, Mormon converts from Denmark, settled this area in the 1860s. "It's been tough to make it.It's gotten to a point where no one will invest and all the young people are leaving. If we don't get this [plant]. Lynndyl will probably case of exist."

The threat of economic decline here has brought IPP the support of many key Mormon religious leaders who oppose any decrease in population or wealth anywhere in Utah, the land they call Zion.

"We have prophecies from high officials of the church that this place will be a hub of wealth." said Merlin Christianson, president of the local Mormon "stake" or diocese.

There are also solid economic reasons for local Mormons to back the project. Besides the jobs IPP could create, it is expected to bring some $32 million extra a year in taxes to rural Millard County. 16 times its present annual collection.

Environmentalists expect little aid from local residents if they decide to challenge the proposed siting of IPP at Lynndy. 130 miles south of Salt Lake City. Utah, with vast, largely untapped, coal reserves, has been eyed for years by California utilities, and Utah usually has shown an equal interest in promoting its energy development.

With widespread local support, a consortium of California utilities, led by Southern California Edison, for nearly 10 years attempted to construct the huge, coal fired Kaiparowits project south of Lynndyl. Kaiparowits, however, was killed in 1976, largely because of pressure by environmentalists outside the state who claimed the project's air pollution would obscure the views of travelers in nearby national parks.

In part to supply the energy needs of the same California cities, IPP dubbed "Son of Kaiparowits," came into existence. At first it appeared IPP would run into the same problems when Interior Secretary Cecil D. Andrus ruled the original IPP site, near the Salt Wash. a barren bowl of land, was unacceptable because of its proximity to Capitol Reef National Park.

Because of California's pressing energy needs, however, Andrus has told IPP officials he would back another, more environmentally sound site. Right now it appears Lynndyl will be that site; officials at Interior, the California State Energy Commission, Utah agencies and the Los Angeles Department of Water and Power appear to favor it.

Part of the reason for this unusual unanimity between often-warring governmental agencies is an understanding that California, which would receive 75 percent of IPP's power, faces a serious energy shortage.

"I usually disagree with the utilities but this time they're right," said Bob Schinn, special adviser to California Energy Commission Chairman Richard Maullin. "Without IPP you'll get progressively worse shortages. They need it to have a reliable energy system in this state."

While governmental agencies appear headed toward accommodation, there are growing problems in negotiations between local Mormon farmers and IPP officials.

Phil Nielson and other landowners have hired consultant Frank Stuart of Salt Lake City to find out how much money they can get for water rights.

Utility officials claim a concerted attempt by farmers to inflate water prices could bankrupt or kill the project. If each acre foot, roughly the equivalent of 350,000 gallons, needed by the project was to be sold at the rates being discussed by Stuart, the local farmers could be asking IPP for as much as $225 million.

"Guys like Nielson want to get rich on that water," complained an embittered Clark Layton, public relations director for IPP.

While Nielson and other Lynndyl area farmers claim all they really want is a "fair price," the haggling over water rights is causing deep concern on the part of some California utility officials.

"It's amazing how things can get like this," said Louis Winnard, general manager of Los Angeles' Department of Water and Power, one of the nation's largest municipally-owned utilities. "If the shortages do come, they'll be a lot of questions asked of all of us and I don't know what our answers will be."