Burnham, New Mexico - In a corner of the Navajo Nation burdened by old and heavily polluting coal-fired power plants, it matters little to many tribal elders that another facility promises to be the most efficient and cleanest of all.

    With two plants already a dozen miles away, the last thing they want is another one even closer, a 1,500-megawatt project barely two miles in another direction.

    "We want the smoke to stop," said 76-year-old Alice Gilmore in Navajo, raising a hand toward the belching plants.

    Others say the $3 billion Desert Rock Energy Facility could invigorate the lagging economy of the Navajo Nation, which stretches across parts of Arizona, New Mexico and Utah. Backers say it would bring $52 million a year in revenues to the tribal government and provide up to 400 jobs on a reservation where unemployment hovers around 50 percent.

    The plan - the largest-ever economic development partnership for the Navajos - has prompted fierce debate pitting that economic windfall against environmental concerns and traditional culture on the 27,000-square-mile reservation, rich with natural gas, uranium and low-sulfur coal.

    Some Navajos believe they are inseparable from Mother Earth and Father Sky - stewards of the land who must live in harmony with the natural world. There are no Navajo words to describe the complexities of power plants; to many elders, they are big stoves that produce electricity, the emissions wild spirits capable of harm.

    "You treat your mother with great respect and love," said Harry Walters, a historian and cultural anthropologist at Dine College in Tsaile, Ariz. "You don't give your mother bad food, you don't take your mother to a place where there is bad air, you don't let her drink dirty water."

    Gilmore grew up tending goats on a homestead on the reservation, and recalls waist-high grass teeming with tiny ground lizards before the coal burning started 44 years ago. While the land is bare now, it would be obliterated by an advancing strip mine that would be tapped for the new plant.

    "Sometimes she cries for it when she's alone, for the land and the destruction," says her daughter, Bonnie Wethington.

    Walters said tribal leaders need only consider the legacy of uranium mining booms in the 1950s and 1970s, which brought cancer, lung disease and death to the Navajos - to know that Mother Earth will retaliate for coal digging and burning.

    Others, however, see a gift in their land's fortune of low-sulfur but high-ash and medium-BTU coal. By various estimates the coal reserve would last a century or more of stepped-up burning.

    "The creator blessed us with this land, where there is an abundance of

    Navajo President Joe Shirley Jr., a staunch supporter of the project, says critics should "stop picking on the little Navajo" when countries like India and China are commissioning a new coal plant practically every week.

    The debate over Desert Rock comes at a time when leaders in Congress and a number of states have begun questioning coal burning, and the volume of greenhouse gases it churns out.

    The project's backers, a private equity group, are trying to build ahead of a possible regulation by Congress, the Environmental Protection Agency or states to limit carbon dioxide emissions, produced in abundance by coal burning that takes most of the blame for heating up the planet.

    The Navajo Nation picked Houston-based Sithe Global Power, which is 80 percent owned by New York-based Blackstone Group (nyse: BX - news - people ), to build what amounts to a "merchant" plant for hire or sale. Blackstone executives say customers won't be hard to find - Phoenix or Las Vegas is the most likely consumer - among hard-pressed utilities in the booming Southwest.

    Because of industry-wide improvements in pollutant-capturing technology over the years, Desert Rock's emissions would be as little as a fifth of the reservation's Four Corners Power Plant to the north. Four Corners, a 2,000-megawatt plant co-owned and operated by Arizona Public Service, routinely ranks No. 1 on dirty-power lists compiled by watchdog groups from emissions reports to the EPA.

    But Desert Rock would hardly be a pollution slouch, despite new emissions technology.

    Every year, according to figures compiled by the EPA, the station would pump out 6,644 tons of sulfur dioxide and nitrogen oxides, which are components of acid rain; 5,529 tons of carbon monoxide; 570 tons of lung-busting particulate matter and 166 tons of smog-forming volatile organic compounds, plus trace amounts of lead and mercury.

    The EPA has yet to approve an air-quality permit, which Sithe Global first applied for in 2004. Sithe and the Navajo Nation's Dine Power Authority sued March 18 over the agency's delay, claiming the tribe is losing $5 million in tax revenue for every month the permit is held up. The Bureau of Indian Affairs already has signed off on a lease.

    Nathan Plagens, vice president of Sithe subsidiary Desert Rock Energy Co., believes the risk of more stringent carbon regulation will "work itself out" in a way that won't derail Desert Rock. But he said the project is stalled because it's seen as politically incorrect.

    "It's all about politics. We've met all of the requirements, done all of the work, and yet we're still waiting," said Christopher Deschene, an attorney for the Dine Power Authority, the tribe's partner in the project. "This is our backyard. We can handle this."

    The EPA says it was initially delayed by climate-modeling uncertainties for a region that includes several national parks, and then by nearly 1,000 mostly negative comments posted on the agency's Web site. Air-permit technicians say they have a duty to answer each of the comments.

    Added to the debate is a recent analysis of government temperature data that shows the interior American West is heating up at twice the global rate.

    "We think we're doing our job as best we can - the good technical work that we are required to do," said Colleen McKaughan, a Southwest region deputy air-division director for the EPA. She declined to provide a timeline for action.

    Environmental groups have vowed to keep fighting any EPA permit.

    "There no such thing as clean coal," said Theodore Spencer, a climate policy analyst for the Natural Resources Defense Council. "Coal power is pretty much the dirtiest power there is, and that plant would do nothing to address global warming emissions."