To get the rock needed for making pavement and concrete, miners want to dynamite and dig up thousands of acres in Lee and Collier counties that's currently habitat for the Florida panther.

When Central Florida's phosphate miners are done digging up their fertilizer ingredients, they're required to restore the land. Not limerock miners. Instead their pit is converted into an artificial lake and the property around it subdivided and turned into waterfront lots.

That makes the loss of panther habitat permanent.

"That's not the direction we want it to head," said Laurie Macdonald of Defenders of Wildlife, who sits on the federal committee trying to figure out how to expand a panther population currently around 100 to 160.

To environmental groups, the miners' suburban developments are slipping in a back door, creating sprawl and not getting a proper vetting.

"Many of these mines are located in rural areas where development may not be appropriate," contended Amber Crooks of the Conservancy of Southwest Florida. Usually the land is farmland, swamp or forest before the mining begins — places where development would likely get closer scrutiny for its impact on panthers if it weren't a mine first.

In December, the Conservancy of Southwest Florida, the Sierra Club and the Center for Biological Diversity sued the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service over the permit for a 970-acre mine known as the Hogan Island Quarry, in part over the future development of the land.

Federal wildlife officials must review the mining proposals to gauge their impact on the future of the panther, which has been on the endangered species list since 1967. Records reviewed by the Times show the Fish and Wildlife Service and the Corps of Engineers, which issues permits for the loss of wetlands, have done nothing to stop the conversion of mining property to suburban development.

Permit reviewers say they're hampered by a lack of cooperation from some mining firms.

"Some mines will not give us their end plans," said Tori Foster of the U.S. Fish and Wildlife Service. "There are constraints on what we're able to ask."

Instead, she said, they have to figure it out from clues in the permit application, such as whether there's any land designated for preservation. If not, she said, "then we consider everything on the property to be impacted" by mining and development.

Tunis McElwain, chief of the corps regulatory section in Fort Myers, says his agency is focused solely on the wetlands. Even if development is slated for thousands of acres of uplands around where the mine would be, it's not something they ask about.

The fact that the rock mines will someday become deep lakes surrounded by new houses is hardly a secret.

"We were very cognizant of that," said Jim Beever, principal planner with the Southwest Florida Regional Planning Council.

One Naples-area development on the site of a former mine is even called "The Quarry." Another mine recently approved by wildlife officials is owned by a builder, Lennar Homes, not a mining company. A third, the Hogan Island Quarry, is shown on a consultants' map at a spot labeled "Town Node."

"Development of the land could be the best use for the water and environmental resources there," said Matt Arbuckle, a land manager for Vulcan Materials, the nation's largest producer of rock and gravel for construction and owner of Florida Rock, a longtime miner in Florida.

Other options for the post-mining landscape include turning the mine into a reservoir or converting it into a golf course like the Quarry Course at Black Diamond in Lecanto, he said.

"We work with the regulatory agencies to minimize our impact on the environment as much as possible," he said.

But the main feature left by the mines, the artificial lakes, are no boon to the environment, Beever said. They go too deep to mimic natural Florida lakes and thus lack oxygen to support any aquatic life.

A further complication is that the mines — and the subdivisions that follow — are being built in an area important to recharging the aquifer, Beever pointed out. A Lee County study said there's no need for new mines for decades because the rock supply from existing mines is sufficient.

Nevertheless, a couple of years ago, property owners in Lee and Collier counties applied for a dozen permits for new mines, McElwain said. Florida's mortgage meltdown had left would-be developers unable to build, he explained. As a fallback they wanted to mine that 19,000 acres, figuring they could then develop it in the future.

But when the corps announced it would conduct an analysis of the cumulative impact of all those mines, all but four withdrew their applications, McElwain said. That ended talk of a cumulative study, although the Conservancy says mines totalling 14,000 acres of impacts still await permits.

In their lawsuit over the Hogan Island Quarry, the environmental groups argue the agencies should still try to gauge the cumulative impact. In 2004, a federal judge invalidated a permit for Florida Rock to dig a 6,000-acre mine over the same issue.

"When considered in isolation, most individual projects would impact only small portions of potential panther habitat," U.S. District Judge James Robertson wrote. "However, when multiplied by many projects over a long period of time, the cumulative impact on the panther might be significant."

The Fish and Wildlife Service biologist who reviewed the Florida Rock permit, Andy Eller, had tried to object to it but was overruled by his bosses and fired. Eller was vindicated by an independent scientific review and rehired, but reassigned to another part of the country with no panthers.

Times researcher Caryn Baird contributed to this report. Craig Pittman can be reached at craig@tampabay.com or follow him on Twitter @craigtimes.