The Salmon Trout River is a place of natural peace.

If you visit the river, which is on the Yellow Dog Plains, near Marquette, you will likely hear nothing but the wind, the sounds of water, or maybe, in the distance, thunder rumbling over the vast wilderness. The plains are part of 576,000 acres of undeveloped timberlands, and are near the edge of the McCormick Wilderness—a remarkable stretch of 17,280 acres of untouched, natural landscape.

But if state officials allow a Utah mining company, Kennecott Minerals, to bore a sulfide mine directly underneath the river there, environmentalists say it will transform a portion of the area’s natural beauty into a heavily industrialized site.

"We don’t believe this is an appropriate spot for a large-scale industrial development," said Marvin Roberson Jr., a forestry specialist with the Sierra Club. "We would be opposed to a Holiday Inn at this location, or anything else that would cause the level of traffic and development that is proposed with this."

Kennecott, a subsidiary of mining industry international giant Rio Tinto, of London, is planning to build the mine on a 90-to-100 acre site on the Yellow Dog that is accessible by gravel roads from Big Bay. The mine, known as the Eagle Project, would involve both state and private land.

Jonathan Cherry, project manager for Kennecott, said the mining can be done safely. In an interview with the Great Lakes Bulletin News Service, he claimed that every aspect of the mine has been designed to protect the environment.

"We believe it can absolutely be done safely both from a human health perspective and also with the environment," Mr. Cherry said. "One of the things that I think (has been) lost in the debate is that we are very sensitive and aware of the environmental implications, but at the same time you have to remember that we are going to have people underground there. It has to be safe for the people."

Kennecott gained access to the lands through the leasing and purchasing of more than 500,000 acres of mineral rights from private entities and the state. The private purchase of the mineral rights was made from Ford Minerals. The state lease of mineral rights unfolded through the Department of Natural Resources under the administration of former Michigan Governor John Engler.

Noted environmental lawyer James Olson said the decision by the Michigan Department of Natural Resources to lease out the land in the first place was not wise, and triggered the proposal for the mine.

"Those are the decisions, the flaw that underlies all of this," Mr. Olson said. "What is going on with the State of Michigan is that they don’t have the sense of what they have in the Upper and Lower Peninsula—that this could even be leased for mining to begin with. They could have simply said no, and they don’t have to give any reason for it. It’s a violation of the public trust of Michigan."

Once the mineral rights were secured, Kennecott performed an extensive search and found an extremely valuable chunk of nickel and copper stretching underneath the Salmon Trout.

"We have been looking for metallic mineral deposits in this area for quite some time, over a decade," Mr. Cherry said. "It was in 2002, through some geophysical techniques and through an actual hole in the ground, that we discovered an ore body up here."

The chunk of rock the company wants to extract is about 85 percent nickel and 15 percent copper. Kennecott won’t say how much the nickel and copper are worth, but most believe the ore body, if retrieved, is worth a staggering amount of money.

"I’ve heard estimates from $1.5 billion as of four years ago to $13 billion," said the Sierra Club’s Mr. Roberson. "It’s clearly a significant, gigantic ore body. They (Kennecott) are the only ones who have the data."

Mr. Cherry said any amount of minerals mined from the state-owned portion of the mine site would earn royalties for the state’s natural resources fund, but would not say how much the company expects to profit.

"As a company policy we don’t disclose the profit that would come from it," Cherry said. "Obviously, if it didn’t make money, we wouldn’t be doing it.

"When the ore body is put into production, those minerals that come from the half that are leased from the state, we actually have to pay a royalty to the state," Cherry said. "It could be anywhere from $25 to $50 million."

Kennecott said the mine will generate about 120 fulltime jobs that will last for about a decade.

"Our goal is to have at least 75 percent local hire," Mr. Cherry said. "A combination of hourly jobs to management jobs everything from mechanics to underground miners to truck drivers to engineers and scientists."

The jobs will offer an average salary of $40,000 not including benefits. This is a fine wage in Marquette, but critics say the short life span of the mine will perpetuate another boom-to-bust mining cycle in the Upper Peninsula.

Complicating the issue is the fact that the nickel and copper are encased in sulfur. This means that when the minerals are removed from the ground, the process can result in the production of a dilute form of sulfuric acid.

Mr. Cherry contends the mining can be done safely even if it involves sulfur. He said the industrial site would include environmental control facilities and "liner" systems to contain any possible acid leakage. The site would also include a 10-million gallon water treatment plant. A sloped tunnel will lead to the ore.

"It will be brought to the surface, it will be put into trucks and shipped off site to a railhead, and at that point it will go to a processing facility," Mr. Cherry said. "There is no processing of ore material on site. This is essentially an underground rock quarry."

But opponents say their concerns are significant. The biggest one seems to be the feeling that the operation would threaten the plains’ beauty and peace: Besides the mine head instillation, Kennecott’s plans calls for massive trucks coming and going from the rural site approximately 40 times per day.

Another fear is that the mine could cause the river to collapse, a possibility that one scientific analysis of the area said should be taken seriously. The DEQ, which will decide as early as next month whether to issue a permit for the mine, originally failed to release documents concerning that possible collaps. The agency said the withholding was an accident.

In addition, the river is home to the coaster brook trout, a fish species that has seen dramatic declines in its population.

"There is a very high potential for contamination of groundwater," said Michelle Halley, an attorney fighting the mine on behalf of the National Wildlife Federation. "The concerns about the water are very important. The potential for drawdown (of pollution) in the wetlands and the river are very real. So far, that’s something the company hasn’t event acknowledged."

A map of Kennecott’s acquired mineral rights shows it owns or leases mineral rights to vast amounts of the Upper Peninsula—more than 500,000 acres. Ms. Halley believes that if the mine in Big Bay is approved by the DEQ, then more are likely come.

"It’s very clear this is the first of many prospects they would like to develop," Ms. Halley said. "We are looking at a big change in the quality of life in the U.P. if this occurs, and a big change in how the U.P. views ourselves and how the rest of the world views us."