When the rainy season comes to south Florida, the region becomes saturated with water. If it's not falling from the sky, water from swelling creeks, rivers and swamps overruns the landscape. This water is the lifeblood to Everglades National Park, and it's a key natural resource of Big Cypress National Preserve, a 728,000-acre swath of swamplands.

During the rainy season, as much as 90 percent of Big Cypress is awash; sopping, soaked, and filled to the brim, and then some. It's this incredible deluge that gives the park much of its life. That's evident by the massive stands of bald cypress, trees whose tangle of roots have adapted to being underwater much of the time.

Then, too, there's the freshwater marl prairie, a prairie built up in part by calcium carbonate particles that are home to various algae. A landscape of muck and sawgrass during the rainy season, the marl prairie is one of nature's incredible filters, ever so slowly draining the rainfall.

Within this setting you can find Great White Heron; the anhinga, a bird never really seen beyond Florida and whose cousins are more commonly spotted in South America and Africa; the brightly feathered and hard to spot purple galinule, and; the Florida panther, one of the most endangered animals in the United States.

The panther is only the most obvious endangered species in Big Cypress, the poster child, if you will. Other threatened and endangered species in Big Cypress include the red-cockaded woodpecker, the American wood stork, bald eagle, Everglades snail kite, Cape Sable seaside sparrow, West Indian manatee, American alligator, and eastern indigo snake.

Within this biologically rich ecosystem runs another creature, one that prowls on four knobby tires that inevitably claw and tear at the terrain, rutting it and redirecting the pulse of water that flows across Big Cypress. For many Floridians who live around Big Cypress, driving their off-road vehicles into the preserve -- which was designated in 1974 -- has been a longstanding tradition. Many use these over-grown rigs to reach hunting camps, others for an afternoon outing.

ORV use of the land now found within Big Cypress dates to the 1920s. Down through the decades, unregulated ORV use has burgeoned, leading to the creation of more than 23,000 miles of dispersed trails. In 2000, then-Superintendent John Donahue, acting on biological information and suitability studies indicating that ORVs were damaging ecosystems and disturbing the Florida panther, implemented an ORV plan that aimed to cut those 23,300 miles of dispersed trail down to just 400 miles of designated trails.

In Big Cypress's so-called Bear Island Unit, that plan called for a reduction of 55 miles of primary trails to just about 30 miles of primary trails and an unspecified amount of secondary routes.

Earlier this year, though, preserve Superintendent Karen Gustin determined that those 20 miles of closed trails could be reopened. That decision spawned a threat from environmental and conservation groups, including The Wilderness Society, the Sierra Club, and Defenders of Wildlife, that they would go to court to overturn Ms. Gustin's decision.

The filing of the lawsuit is said to be imminent.

In announcing their legal intentions, the groups alleged that the National Park Service, by reopening those 20 miles of ORV trails in the Bear Island Unit, had violated not only the Endangered Species Act but also the Clean Water Act, the National Park Service Organic Act, and even the preserve's own ORV Management Plan and Supplemental Environmental Impact Statement.

More specifically, they contend that ORV use in Big Cypress "has impacted wildlife populations and habitats through modifications to water flow patterns and water quality, soil displacement and compaction, direct vegetation damage, disturbance to foraging individuals, and ultimately, overall suitability of habitats for wildlife."

Superintendent Gustin maintains she was operating well within her authority to reopen the ORV trails. By developing travel plans for each of the preserve's various units, Big Cypress managers will establish a well-defined trail network, one that will be easier to regulate, the superintendent said.

“Prior to this plan being written, there was dispersed use all over the place. Negative resource impacts. I think everybody agrees with that," said Superintendent Gustin. "And the plan was meant to No. 1, protect resources, and No. 2, to get rid of dispersed use. That’s a huge goal for us. To get rid of dispersed use completely, we have to have a trail system in place so that we can enforce the regulations to keep those people on the trails."

As to concerns that allowing 20 more miles of ORV trails in the Bear Island Unit will be detrimental to the survival of the Florida panther, Superintendent Gustin said the latest biological information on the panther says it can co-exist with ORVs at the proposed levels.

“Back in the mid-90s to the late 90s when this plan was being written, when that lawsuit was going on, there was a general consensus, a feeling among the Park Service and the (U.S.) Fish and Wildlife Service that Bear Island was the only habitat really suitable for the Florida panther. It’s high and dry. It’s the highest and driest area of Big Cypress," she said.

"In the mid-90s, eight Texas cougars were brought in to breed with the Florida panthers that were in existence at that time. I think the population was down to about 30. Those panthers bred, they were very successful, and we now have approximately 80-100 panthers in south Florida, and we say approximately 30 of those panthers use Big Cypress on a regular basis," she continued.

"We have found subsequent to that genetic reintroduction program that all areas of Big Cypress are suitable for panthers, and in fact panthers are using all of Big Cypress. So, yes, Bear Island is important habitat for the panther, but it’s not the only habitat that’s being used by panthers. All of Big Cypress is being used."

Oddly, while the Fish and Wildlife Service did support Superintendent Gustin's decision on the Bear Island trails, it did so based on what the Park Service planned to do in the future.

In conclusion, the Service believes that the commitments outlined in your February 15, 2007, letter are sufficient to demonstrate the NPS' intention to comply with the terms and conditions of the July 14, 2000, Biological Opinion with respect to the Bear Island management unit, Paul Souza, the field supervisor of the Fish and Wildlife Service's South Florida Ecological Services Office, wrote in mid-February.

Among the Park Service's proposed commitments were plans to conduct a carrying capacity study of panthers in the Bear Island Unit and a study evaluating the impacts of ORVs on panther movements. Why those studies weren't performed before Superintendent Gustin decided to open up more ORV trails in the Bear Island Unit, and why Mr. Souza didn't insist on those studies before supporting her decision, seems incredible to Kristen Brengel of The Wilderness Society.

"In our meeting, Paul Souza talked about anecdotal evidence, none of which is memorialized in his memo. The fact is that FWS has not completed any studies in order to open areas to off-road vehicles. They violated the law as did the Park Service," said Ms. Brengel.

"The superintendent appeared to have every intention to open up more Florida panther habitat to damaging swamp buggy use. If she really intended to take a careful look at wildlife issues and involve the public, she would have waited for the studies to be completed and held a meeting that included the public rather than stacking the deck by inviting almost only off-road vehicle enthusiasts," she added.

"This decision is horrible and sad for all national parks."