OCHOPEE, Fla. -- I'm following Clyde Butcher into the nearly waist-deep water of the Big Cypress Swamp and trying not to think about that old hiker's joke about the hungry grizzly bear. Yeah, the one with the punch line that goes, "You don't have to outrun the bear. You just have to outrun one other person."

There are no grizzlies here, but the joke has popped into my head and won't shake out because the woodsy swamp we're about to slosh through is the literal equivalent of that otherwise familiar figurative phrase: ass deep in alligators.

Butcher is 64 and roundly robust; a man who looks more like Santa Claus than Swamp Fox. He looks like Santa, though, in a wide-brimmed straw cowboy hat to shade his rosy-cheeked, white-bearded face. He's carrying a 5-foot-long hiking stick that also could double as a "gator poker" in a pinch. I could probably outrun him on dry land, but here, in the middle of the Big Cypress National Preserve, he's got home-swamp advantage on me.

We are out behind Butcher's home and photo gallery, just off the Tamiami Trail, a two-lane asphalt ribbon from Miami to Tampa. Here it lays atop an east-west causeway through the Everglades, where the road's irregularly spaced wide shoulders harbor air boat marinas, Miccosukee reservation casinos and bingo parlors, fry bread stands and sun-bleached roadhouse restaurants specializing in frog legs and barbecue.

Butcher's lived here on Orchid Isle, a 13-acre beachhead of sandy fill and cypress, 50 miles west of Miami, for 20 years. In that time he's taken countless walks through these cool, dark brown waters with friends and visitors to show off a wild orchid and iris framed waterscape that he loves to photograph -- and to push the environmental policies he believes are needed to save it and the rest the globe.

On this day Butcher's not carrying his usual 40-pound pack containing one of the large format cameras he regularly totes into the swamp. Using one of three big Deardorfs or a Wisner he's made a living and a reputation producing wall-wide, black-and-white, land- and waterscapes. The starkly vivid photographs have won him an international following and spawned comparisons to Ansel Adams.

But his focus today, on this swamp walk with a dozen journalists, is on some of the conservation issues even he has trouble fitting into a viewfinder.

"Everyone wants to save the bits and parts of the environment, but the world is being threatened by climate change," Butcher said. "We have to do something about that first. There's no sense saving the environment here in the Everglades because it's going down if we can't do something about global warming."

The fresh water swamp that is big Cypress is particularly fragile because it is just 8 or 9 feet above sea level. It would be inundated by rising ocean levels associated with most climate change projections.

efore we step into the water for this wet one-mile slog -- Butcher calls these hikes "muck-abouts" -- he strolls over to an empty "gator nest" that's little more than a depression in some dry grass a few yards from the shoreline of an open water "hole" or pool that's about 30 yards across.

He points out the half-dozen baby alligators, just 8 inches long, clinging to an old log under some brush. He cautions against stepping close enough for a photo. Their mother is likely in that pool, he says, and might come to her children's defense with a rush.

He talks about how he never hikes in the swamp alone, how alligator eyes glow yellow in the dark, and how one local man he knew, Oscar Gladsman, boasted years ago that he killed 23 alligators in a hole no bigger than the one we're standing beside. The hole is similar to one out in front of the gallery, next to a small parking lot where two alligators were sunning themselves until we drove up. They moved sluggishly out of the gravel and across a narrow grass berm before slipping quickly into the pool where they imitated squinty-eyed logs.

As Butcher walks along the shoreline to the end of the pool where cypress trees are growing out of the water, he notes that the number of water moccasins appears to be down because the alligators eat them. This factoid is supposed to be comforting.

When Butcher steps into the water, he sends a series of small waves lapping against the shaggy-barked cypress that form a kind of porous picket line between our water route and the open hole where mom alligator is submerged.

One of the first things I notice as the cool water of the swamp seeps quickly into my shoes, surrounds my ankles and climbs up my calves to my knees and beyond is that the Big Cypress doesn't smell like a swamp. Although the vegetation is broad-leafed and lush, there is no rotting smell or heavy mud.

Butcher explains that the swamp is rainwater and spring fed and has a slightly higher elevation that the surrounding Everglades.

"That couple of feet of elevation is enough to keep the water flowing and keep out the pollution from the sugar plantations up north," he says.

e walk haltingly, in single file, on a water trail through cypress and sawgrass.

The sky has turned gray as the cypress and begins to spit rain. We use our hiking sticks feel ahead under water for roots that could trip us or deeper holes that could cause us to slip in up to our armpits. Whatever vague markings there are on this water route must appear only in Butcher's head.

I'm reminded that on the way from Miami, a friend who has been on these walks before recalled hearing that Butcher once got lost in the swamp while out on a photographic excursion and took more than an hour to reorient himself and find his way back. This again fails to comfort.

As we wade through the cypress, only a few with trunks bigger than 10 inches around, and fewer still that to my untrained eye look in any way distinctive, Butcher acknowledges that in the wet, Spanish moss dripping heart of the swamp, the size of the trees don't quite live up to the name of the place. The cypress were much bigger, he says, until the 1950s when much of the region was timbered, the logs carried out on narrow gage railroad spurs built deep into the swamp. The rot-resistant, durable wood was popular, he says, for stadium seating, deck furniture, sewer pipes and pickle barrels.

Because the vegetative mat where most are rooted may be only several feet deep, mature cypress trees rely on an extensive system of horizontal roots. Cypress "knees" grow up from the roots to poke out of the water and provide the extra stability necessary for the trees to weather hundreds of years of storms and hurricanes. They also provide hand-holds to help us balance as we trip along the rooty bottom.

Charles Kropke, a naturalist with Dragonfly Expeditions, a local eco-tourism group, reaches into the water and holds up what he proclaims is "the sexiest plant in the swamp." It looks like a sopping wet hunk of spongy brown bread.

It is, he says, a chunk of periphyton matting, an oozy benthic algae that anchors itself to the base of other plants in the swamp and is the foundation of the Everglades food web.

It's thriving here in the Big Cypress but disappearing elsewhere in the Everglades where runoff from sugar industry fields, farms and residential developments has elevated phosphorous levels to more than the algae can bear. As the algae vanish, the tiny creatures that live in it on it vanish too, with a ripple effect throughout the whole food chain.

Butcher points at the base of one of those cypress and reaches down to pull up a ramshorn snail. Those snails and the Florida apple snail, he says, are the only food of the snail kite, also known as the Everglades kite, a raptor on the endangered species list. It doesn't help that the apple snails are also becoming rare.

"The environment is becoming a war, a war more important than Iraq," Butcher says. "It's a war of survival but most people don't realize that yet."

Butcher does. From architecture student to self-taught photographer to a celebrated photographic artist and environmental activist, his awareness of what is happening to the natural world has evolved into his cause. And each Labor Day weekend, he opens up his property and leads swamp tours, designed to highlight problems and spur people into action.

Last year over that three-day weekend, 1,300 people toured his corner of the swamp. Butcher charged them $20 each, and donated the money to local environmental groups.

lose to the end of the hike, Butcher stops in a spot where the water trail opens up into another small pool surrounded by a necklace of ferns and green shrubs, including swamp apples and coco plums that aren't blooming now but will in the spring. Thigh-deep in the swamp, he gives a speech that it seems like he's delivered at least a few times before while standing against this picture perfect backdrop.

"I've gone all over Florida and the world to take beautiful photography. Here I run eco-tours. We are activists here," Butcher says. "Thomas Paine wrote, 'We have it in our power to begin the world anew.' Well, Florida is on the precipice. Do we preserve the land and find a way for people and animals to have a place here?

"Florida is a beautiful place. It was paradise for early explorers. I try through my walks here to get people to see what it is we need to protect. We have it in our power. We just need the people to do it."

A few wet steps and we gain the back side of Orchid Isle. Dry land. Water squirts out of our shoes with each step. When we reach a small shed, Butcher collects the hiking sticks he handed out when we left and notes with a smile that all have been returned.

"This," he says as he stows the sticks, "is going to improve our overall hike completion percentage."