In eastern Collier County, an hour's drive inland from the waterfront condos of Naples, amid cattle ranches and tomato fields and cypress swamps, panthers prowl the night. For now.

Panthers can easily travel through this swath of privately owned land seeking deer and hogs to eat. The wide-ranging predators move between the Big Cypress National Preserve and the Florida Panther National Wildlife Refuge to the south and the Okaloacoochee Slough State Forest and Corkscrew Swamp Sanctuary to the north.

Parts of that land are so important for the panthers' future that in 2006 a group of scientists included it in what they called "the primary zone." That means it's land that should be preserved at all costs or else risk the extinction of Florida's official state animal.

But now federal officials are considering a proposal from 11 major landowners in that area to allow them to build thousands of new homes and businesses across 45,000 acres and also open new sand and gravel mines. That acreage, targeted for development over the next 50 years, includes about 20,000 acres of primary panther zone. In exchange, the landowners promise to preserve another 107,000 acres, although about half has already been preserved through a voluntary program.

The proposal is called a "habitat conservation plan," although opponents scoff at the second word in the name.

"It kind of will determine the fate of the Florida panther," said Amber Crooks of the Conservancy of Southwest Florida, one of the environmental groups opposing the plan. "Three hundred thousand people are going to be moving into this area."

The habitat conservation plan has split Florida environmental groups. While some are trying to stop it, Defenders of Wildlife, the local Audubon chapter and the Florida Wildlife Federation have been working with the landowners for a decade to make the plan better for the panthers and 18 other imperiled species that would be affected by it.

"It's a very ambitious plan that, if it's done properly, could advance the cause of conservation," said Elizabeth Fleming of Defenders of Wildlife's St. Petersburg office.

The groups supporting the plan are shifting their strategy after years of trying to block other developments in panther habitat. The reason, Fleming said, is simple: "They hardly ever get stopped."

In 2010, the Times analyzed the federal agency's response to development in panther habitat and found it had not tried to block any projects since 1993. It allowed development to wipe out 42,000 acres of habitat just as the population was growing from 20 to about 200 cats. Former agency employees said that every time they tried to stop a development, they were told that it would be a political disaster.

So when the landowners approached the environmental groups about joining forces, the prospect seemed appealing. To sweeten the deal, the environmental groups that support the plan get to appoint four of the seven members of a board that will oversee a $150 million fund to help panthers.

However, when supportive environmental groups have suggested changes, they have met with limited success.

The most controversial part of the plan deals with what's known as an "incidental take permit." Such a federal permit gives the landowners immunity from prosecution for harassing, hurting or killing panthers while pursuing legal activities.

The No. 1 cause of death for panthers is being run over by cars. The development will add at least 300,000 more car trips to the area that's now largely devoid of them. Yet the 11 landowners don't think they should be held accountable for that.

"It's something we have discussed and disagreed with the landowners for some time," she said. "They are sticking to their guns. The landowners don't believe they're responsible for the taking of the panther if someone hits a panther with a car."

Some critics fear the permit will allow hunting panthers, but that will remain an illegal activity.

Christian Spilker, a senior vice president of Collier Enterprises, has been the primary spokesman for the 11 landowners. He said that legally, making the developers responsible for what thousands of drivers do or don't do is wrong.

"I don't control your driving, or your texting and driving, that might have caused you to run over a panther," he said. But he promised the U.S. Fish and Wildlife Service will analyze the impact of all those new drivers on the panther population.

The wildlife agency did not draw up the conservation plan. It was created by contractors hired by the landowners. But federal taxpayers helped pay for it, handing over $765,357 in grants. Spilker said that the final price tag for the landowners was "north of $1 million."

The government also failed to persuade the landowners to make a crucial change in the habitat conservation plan. When the wildlife agency proposed reconfiguring the development to avoid more of the primary zone, the answer was no.

"They explained it just wasn't feasible for them," said Connie Cassler, the federal biologist overseeing the agency's work.

Spilker said that not everything labeled primary zone is valuable panther habitat. He contended that what's important are the remaining corridors for panthers to travel along, which the landowners did agree to widen. He compared reconfiguring the development to pulling on too many threads: "The whole thing begins to unravel."

The wildlife service public comment period on its draft environmental impact statement for the plan and the take permit ends Monday. The agency must make a final decision by April. That's far faster than it would have been in the past, because of Trump Administration orders to speed up agency rulings in such cases.

So far nearly 1,000 people have weighed in, many raising concerns or opposing it.

Senior news researcher Caryn Baird contributed to this report. Contact Craig Pittman at craig@tampabay.com . Follow @craigtimes.

Want to be heard?

The deadline to comment on the Eastern Collier Multi-Species Habitat Conservation Plan is Monday, Dec. 3. To comment online, click on this link: http://www.regulations.gov. Then follow the instructions for submitting comments on Docket No. FWS-R4-ES-2018-0079. You can also mail comments to Public Comments Processing, Attn: FWS-R4-ES-2018-0079; U.S. Fish and Wildlife Service Headquarters, MS: BPHC; 5275 Leesburg Pike, Falls Church, VA 22041-3803. The agency will accept comments postmarked on or before the deadline.