By Chuck McGinness

Palm Beach Post Staff Writer

On a busy stretch of Interstate 75 near Ocala, a piece of man-made wilderness is rising above the highway. When it opens in September, a 17-foot-high and 52-foot-wide bridge will be lined with native oaks, pines, and saw palmettos. A path made of finely crushed oyster shells will run down the middle of the 200 foot-long span.

The $3.2 million elevated nature trail will reconnect two pieces of the Cross Florida Greenway that were split 30 years ago by highway construction. By day, hikers, bicyclists and horseback riders will once again be able to traverse the 110 acre recreation and conservation area without having to stop for speeding cars or trucks. In the dark of the night, deer, foxes and possums can scamper across the bridge to avoid becoming road kill.

The "1and bridge" - the first ever built in the United States - is the latest example of efforts by state and federal transportation departments to protect wildlife along highways and to link fragmented natural areas.

In the past decade, special crossings have been built for Florida panthers on Alligator Alley and State Road 29 in southwest Florida, and for black bears on SR 46 in north central Florida. Plans are in the works to build additional bear underpasses along roadways in the Wekiva River Basin northwest of Orlando and crossings for deer along U.S. 1 in the Florida keys. Work will begin next year on a second land bridge along I-95 in Flagler County to join the Florida Agricultural Museum with the Princess Place Preserve.

This bridge, just south of Ocala sits on land where the Cross Florida Barge Canal was once envisioned. Construction of the canal began in 1935, but was stopped a year later because of a lack of money. Work resumed in 1964, but a series of lawsuits that claimed the project would destroy natural habitats, led to its demise in 1990.

"We took something that was environmentally unsound and was going to destroy nature and turned it back into something good," DOT project engineer Alan Bryant said. But wildlife advocates and environmentalists say much more needs to be done in planning new highways and rebuilding old ones to make them more environmentally friendly. Roads should not run through preserve areas, they say, but if there is no other alternative, roads should be built on pilings to cause the least disruption to wildlife in their natural environment.

"If we don't do it right at the outset, we're going to pay in the future with the loss of important, significant resources," said Laurie MacDonald, state representative for Defenders of Wildlife, a national, nonprofit conservation organization. "I don't think there's too many places in the state where you can go where there are no roads."

Each year, millions of mammals, reptiles, amphibians and birds are killed on the nation's highway while looking for food or trying to reach mating or nesting sites. Many are slow moving tortoises and snakes that aren't as popular as endangered species, like the panther and black bear, but an important part of regional ecosystems.

The problem also effects motorists' safety. More than 200 people are killed and thousands injured annually in vehicle collisions with animals, according to the Federal Highway Administration.

Public awareness of the need to blend wildlife conservation into transportation projects has increased significantly in the past few years, according to federal ecologist Paul Garrett. The $218 billion Transportation Equity Act for the 21st Century, or TEA-21. approved by Congress two years ago provides $3 billion to states for environmental enhancements. "Critter crossings" were added as an eligible improvement, Garrett said.

In California, scientists are studying how desert tortoises use storm drains to move under a highway in the Mojave Desert. Researchers in Massachusetts are monitoring how roadway tunnels aid spotted salamander on their annual migration.

"Florida is one of the states that has been very active in this area," Garrett said. One of the more innovative projects is located at the Paynes Prairie State Preserve near Gainesville. Thousands of animals from 80 different species were killed every year on a 2-mile stretch of U.S. 441 that runs through the preserve. A 3.5 foot wall with 6 inch lip at the top - similar to walls in zoo serpentariums - now prevents animals from reaching the highway. Animals move along the wall to one of eight underpasses.

-200"If you do these studies up front to know where to place the crossings, wildlife will use them," said state ecologist Gary Evink. "I think people see enough dead animals along the roads to realize this is something we need to be concerned about."

The land bridge on I-75 in Marion County was modeled after wildlife overpasses in the Netherlands called ecoducts. The ecoducts link natural areas that were split by highways and are part of migratory routes for moose and other wildlife.

State officials said they went to great extremes to give the bridge a sense of "natural connectivity" so it blends into the surrounding area. Stones covering the walls were gathered from horse farms around Ocala. Mature pines and oaks aren't found in plant nurseries, and some of the trees are being imported from Arizona, said the DOT's Bryant.

"I suspect quite a few animals will use it, if they have a strong urge to get across the highway; said Dave Bowman, a wildlife biologist at the state Department of Environmental Protection.

But MacDonald of Defenders of Wildlife said it's too early to tout the bridge as an environmental success. MacDonald said she wonders if animals will use the same path tromped on by people. "That's not to say it won't work," she said. "It may be trying to serve to many purposes, but I give a lot of credit to the people in the state who are trying to do these things."

State environmentalists are sure it will work. Workers building the bridge said they've already found animal tracks. "I hope there are skeptics so we can prove them wrong", Bryant said.

The 36 panther crossing on the western end of Alligator Alley - the highway connecting Fort Lauderdale and Naples - cost about $20 million. They were put in about 10 years ago as part of a $350 million road widening project.

At each crossing, the road was raised or a bridge was built over a low spot, creating an 8-foot-high, 120 foot wide pathway for the panthers and other animals. Fences along the road direct animals to the crossings. Before the work was done, biologists monitored the panthers' movements with radio-tracking collars and put the pathways where the animals usually crossed the road.

No panthers have been killed or injured on Alligator Alley since the crossings were installed, according to Darrell Land, a research team leader with the Florida Fish and Wildlife Conservation Commission. Before that, several panthers were killed or injured each year on the two roads, Land said.

State engineers and biologists followed a similar plan to design the black bear underpass on SR 46 in Lake County. The 8-foot-high, 24-foot-wide dirt-floor tunnel was put at the spot where bears were most often hit by cars while crossing the highway.

The state spent about $3 million to buy 40 acres of privately owned land in the bears' travel corridor to put in the crossing, Evink said. So far, no bears have been hit near the crossing, he said.

"The bear underpass is a great first step," but the state needs to build additional crossings along the road which runs through the Ocala National Forest, said Jennifer McMurtray, the transportation and wildlife ecology coordinator for Defenders of Wildlife. Also, a 1.5 mile stretch of the road in the most densely populated area of the preserve should be raised, McMurtray said. Highway officials said that's too costly.

DOT officials have been working with University of Florida scientists to develop guidelines to use in deciding where to build future wildlife crossings and bridges. A geographic information system lets transportation planners identify road kill "hot spots" around the state. As well, UF researchers are conducting field studies to evaluate the usefulness of existing crossings.

The state will only build crossings that connect publicly owned land, Evink said. "We don't want a McDonald's or housing development popping up next to a wildlife crossing," be said.

Both environmentalists and highway officials admit there is so much more they can learn about the problems associated with transportation and wildlife. "We're just beginning to understand what we need to do in planning roadway projects, and we ought to he implementing better plans," MacDonald said. "It's not good for people in cars to hit animals on the road."

The Federal Highway Administration has sponsored three international conferences on the topic and a fourth meeting is tentatively planned for next year. Last year's conference in Missoula, Montana, brought together more than 300 people to share information on various solutions, both those that been successful and those that have failed.

Administration ecologist Garrett said despite the gatherings, "I don't think we'll ever get to the point where we prevent all wildlife mortality.