This is basically insane. I am paddling a kayak into a body of water most people think of as a sewer. What should I call this activity? E. coli kayaking?

It's late April in an unusually cool spring for Dallas. I launched my boat 20 minutes ago at the top of White Rock Lake and now am headed up the creek. With a paddle. And an extra paddle, as a matter of fact.

White Rock Creek rises in Collin County three-and-a-half miles southeast of Frisco and flows to White Rock Lake in East Dallas, a distance of 18 miles as the crow flies, but half again that distance in the meandering miles of the creek itself. From the lake it flows southwest another straight-line distance of 14 miles, meeting the Trinity River about six miles south of downtown Dallas.

I've lived in Dallas a long time. I love canoeing and kayaking but far, far from Dallas. The closest places I ever think of seriously for paddling are Galveston Bay, 300 miles south, or rivers in Oklahoma and Arkansas, 300 miles north.

And then there's the story about Dallas not having any nature. It's our origin myth: We're the poor little spot that had no reason for being except for gumption, by golly. Try kayaking in gumption some day.

But lately I have been hearing these odd stories. Urban legends about people who refuse to accept the myth—some kind of Indiana Joneses who strike out into the city's forbidden realms seeking the Lost Treasures of Natural Dallas.

So that's what I'm supposed to be doing today by paddling up White Rock Creek—not Indiana Jones, exactly. More like urban explorer E. Coli Clem.

At this moment I am in my small blue plastic kayak approaching a construction site where crews are building a new bridge at Northwest Highway. Two guys in hardhats are carrying a piece of steel on their shoulders in tandem across the old bridge just ahead of my kayak.

They stop when they see me, and then, while balancing the steel with free hands, lean over the edge, peering at the low, dark passage beneath their feet where I am headed. They smile and exchange meaningful shrugs, almost toppling the steel onto me. They catch it and continue across the bridge with their burden. Just what I need—Abbott and Costello.

The space beneath the bridge is dark and low—a foot or so above my head. I am paddling upstream against a mild current through reefs of wadded Styrofoam and other offal, which I don't want to examine too closely, except that I am keeping an eye peeled for poisonous water snakes. I know these "moccasins" or "cottonmouths" and have great respect for them based on past experience.

Here under the bridge, it occurs to me that this whole E. coli paddling thing was not my idea. On March 14, BJ Austin, a reporter with KERA Radio, did a story about 15 years of hold-ups and snafus in the multi-billion dollar project to rebuild the Trinity River—the part where it flows through the center of the city—and the problems with planned manmade lakes, levee safety, construction of fake rapids for kayakers and so on.

She opened the story with a quick snippet about two guys, Bret Bolton and Donny Hutchinson, who had just kayaked the West Fork of the Trinity River from downtown Fort Worth to downtown Dallas in three days, camping along the way. I was fascinated.

I phoned Bolton. He told me they had guerilla-camped two nights on the edges of golf courses and parks, paddled through sunken trucks and collapsed railroad trestles and discovered a kind of secret wilderness where most people are afraid to go.

So now I am trying to do my own cheapo version. And here beneath the rumbling traffic on Northwest Highway, I must make a decision. Go home. Or gut up, stop looking for snakes and dead dogs. Make an adventure of it the way I might have done as a boy.

When I was little, I lived in Ann Arbor, Michigan, which had a polluted river. We boys were warned never to go near the Huron River, so we spent long summer days building rafts and playing Tom Sawyer on the river. Like this stream, the Huron River was beautiful to us in ways more beguiling than any pretty park could be, probably because the pollution and scary trash kept the grownups away. I'm not sure how much I have progressed.

I decide to press on. The day is cool. When I break out into daylight again on the other side of the bridge the creek is running 40 feet broad and straight down a manmade channel. The surface is coal-black flecked with floating white cottonwood seeds. A tousled wall of green rises above both banks.

I pass beneath another bridge at West Lawther Road, and now the creek begins to dodge left and right between steep mud banks, back on its natural course. Huge old cottonwoods reach down with leafy arms almost to the surface of the water. I glide between their green fingers, completely separate from the man-built universe.

Ahead I see a mother wood duck and 12 ducklings scattered out in the center of the creek. I can't hear her yet, but she's definitely talking about me. The babies are all streaming quickly to her side. She bears for the far bank with her young in tight single file behind her.

I see trash—plastic bags hanging from roots and branches, floating beaches of rotten Styrofoam. But as I go farther upstream, the world around me grows deeper green and quieter. Suddenly I feel like Charles Marlow, the ferry boat captain on the Congo in Joseph Conrad's Heart of Darkness. Maybe if I keep pushing upstream far enough I will find Kurtz, the mad ivory dealer. He should be somewhere in the area where Skillman Street crosses Abrams Road, a mile and a half east of Central Expressway. If I were Kurtz, that's definitely where I'd hang out.

Cell phone rings. Son in L.A. tells me about visiting a home the day before with a stunning view up into Angeles National Forest—a breathtaking panorama of mountains and sky. I tell him I am in my kayak in East Dallas staring at a half-sunken shopping cart.

But beauty, like gold, is where you find it. Same with adventure.

Before setting out, I talked to Randy Johnson, director of horticulture at the Texas Discovery Gardens at Fair Park—an urban bushwhack paddler from way back, a man who slides his canoe down steep mud banks at the end of a rope to find lost pockets of wilderness in the heart of the city.

Johnson told me he once paddled his way far up White Rock Creek, up into the Heart of Darkness, got out and struck overland through the forest to see what he could see.

"I found a homeless encampment out there the size of a small town," he said.

Kurtzville.

Dead ahead I see a long black creature sliding lazily across the surface of the water, thick as a man's bicep, head the tell-shape of a shovel. Water moccasin. Know him well. We have an old understanding. The moccasin's presence here is a marker not for wilderness but for wildness. I can pass him without incident, or I can be stupid and show aggression by shaking a paddle at him, in which case he will attack.

He is wild, not tame, and this place is his world. My GPS shows us at four tenths of a mile from Skillman Street. But his world is a million miles from the land of cages where I live.

A sharp odor assails me. I look around for it. Right beneath my paddle a dead dog straddles a branch, bloated, hairless, buzzing with flies, crawling with maggots. I was just about to hit it with my paddle.

As I paddle ahead the creek twists and bends, swelling to 40 feet in width, choking to 20, swelling again. Then the creek is barricaded all the way across by trash clutched in the branches of a fallen tree. The water is about four feet deep in the center, deeper in some holes, but I am able to get out of the boat next to the bank in water up to my calves. I crawl through an opening in the branches and then pull the boat behind me by a rope. Not far ahead I do the same thing at a larger trash dam.

Now I'm standing on a beautiful little gravel beach. The air is clean and green. Shapes of fish flit past my feet like shadows of birds. The water is semi-clear. I can see only patches of sky through a thick canopy of trees. When I stop moving, stop listening to myself, the world here is quiet and soft, a symphony of bird calls. And yet in the distance I can hear traffic at about the volume of far-away cattle in the country.

On the way back down to the lake and my car, slipping along easily with the current past the place where I saw the moccasin and past the stench of the dead dog and the cloistered ducklings, I round a bend in the creek and two enormous barred owls fly from the same tree in front of me, their diverging flight paths forming a V in the air. I bet Joseph Conrad would have done something very literary with that.

Weeks after I heard BJ Austin's story on the radio and after I had already explored some creeks on my own, I finally met Bret Bolton and Donny Hutchinson, the urban bushwhackers whose exploits on the West Fork had inspired me. Over beers at a bar in Uptown one Saturday afternoon in mid-May, they poured out their story, talking over each other like Chief Martin Brody and Sam Quint swapping tales of derring-do in the 1975 Spielberg movie, Jaws.

They have known each other and fished together for five years. Last year they shared a period of mutual unemployment and heavy fishing, during which they talked about doing a three-day voyage by kayak on the West Fork from downtown Fort Worth to downtown Dallas.

The Trinity, the biggest river contained entirely in Texas, is either more than 700 miles of river or more like 425 if you don't count its various forks. The West Fork arises in Archer County about 125 miles northwest of Dallas and flows through Fort Worth on its way here to join the main branch of the Trinity near the intersection of Loop 12 (Walton Walker) and Irving Boulevard.

Fort Worth, for whatever reason, has been able to complete a lovely remake of the river in its own downtown, replete with kayaking white-water features. Dallas, meanwhile, has stumbled for 15 years without ever getting any of the basic features of its own river project off the ground, unless you count the footings of one make-believe suspension bridge designed by Spanish architect Santiago Calatrava, now in a state of suspended suspension while the U.S. Army Corps of Engineers decides whether it can be safely completed.

The Fort Worth project does not include any faux suspension bridges and certainly does not include anything like the controversial high-speed multi-lane highway that Dallas wants to build out between its flood control levees where floods occur. Maybe that's why Fort Worth's Trinity River project is complete and ours is stuck in the mud.

There is great public focus, then, on the Trinity River in downtown Fort Worth and great focus again 30 miles east in downtown Dallas but no focus on the stretch of the West Fork that meanders from Fort Worth eastward, mainly north of I-30 (Tom Landry Freeway) through Arlington and Grand Prairie.

So what made two responsible family men decide they wanted to mount yellow kayaks and paddle from one city to the other on that abused and forgotten body of water?

Bolton, a 38-year-old Unix software engineer and father who lives in Irving, told me he had read an article about some guys who paddled through Houston on Buffalo Bayou to the Houston ship canal.

"It sounded terribly fun and terribly disgusting at the same time," he said.

Hutchinson, a 34-year-old research technician and soon-to-be first-time father who lives in Fort Worth, said, "Bret and I thought about this for a full year."

Hutchinson, the experienced backpacker of the pair, provisioned them with ultra-light cooking gear and freeze-dried food. Bolton had the two kayaks they needed. Both men studied the system of reservoirs that release water into the West Fork.

If the lakes upstream from them released no water or small amounts, then the water in the river where they were paddling would be too shallow. But if the lakes suddenly released large amounts, the water in the river might be dangerously high and fast.

Bolton found the U.S. Geological Service Web page that posts notices of releases from dams and the downstream water volume. Hutchinson found an iPhone app that allowed them to keep track of the USGS information as they paddled. They timed their trip to avoid major water releases from the reservoirs.

"I looked at the river today on my way over here," he said the day we met. "We would have been killed if we had tried it with that much water in the river."

But then that was also what made them want to do it—the risk and sheer unpredictability. "Who's done this before?" Hutchinson said. "When's the last time?"

I asked how their wives felt.

"We tried very hard not to send out a vibe that this could be dangerous," said Hutchinson, the backpacker.

The river flows beneath steep banks walled by ancient trees. Right above the banks is suburban sprawl, but the two men did not see or hear or sense the world up there. They might as well have been on the Congo River searching for Kurtz. But on this Congo, the white water has steel teeth.

Each was in his own kayak. Bolton said, "The best rapids was somewhere between Highway 360 and Roy Orr Boulevard. There is a railroad trestle that has fallen into the water. We're getting ready to portage around it, and by the time I look at it, we're in it. So we punch right through it. When we get past it, I have the biggest, nastiest gash in the side of my kayak."

Hutchinson said, "We looked back, and we could see metal sticking out of it—re-bar and sections of the trestle."

Note to self: There is a big difference between white water in Arkansas, where you can get wet, and white water on the Trinity, where you can wind up with a rusty steel rod through your neck.

"There's quicksand everywhere," Hutchinson said. "One time we pull up to the bank for a restroom break. I get out and put my left foot in and it sinks up to my ankle right away. I put my right foot in, and it's up to my knees. I go to lift up my right foot, and by the time I put it down, my left leg is up to my thigh."

In seconds, he was in the sand up to his waist and still sinking, with soupy sand dangerously close to pouring over the top of his chest waders.

"I start thinking back. I watch Man Versus Wild [on the Discovery Channel], and Man Versus Wild says grab a stick, whatever you can use as leverage. I grabbed a paddle."

With the paddle as a lever, he pushed against the hard mud bank and was able to get himself back over to his boat. "I basically dragged myself up and laid across the boat and was able to pull myself up on it."

Their boats, by the way, were the super-buoyant "sit on top" models of kayak, kind of like thick surfboards. Hutchinson's maneuver would have been much more difficult in the kind of hollow-hull kayak that you sit inside.

When we talked in the bar that afternoon, one subject animated Hutchinson and Bolton more than their tales of narrow escape. When they strove to describe to me the natural beauty through which they had passed on their voyage, their voices grew earnest and excited. They forgot their beers and finished each other's sentences.

In spite of thousands of tires and countless rusting cars in the water, the West Fork they discovered out there was a paradise. Bolton said, "Except for the bald eagle, we saw absolutely every bird of prey in North Texas, including... "

"Peregrine falcons," Hutchinson interrupted.

"Hawks."

"Vultures—both kinds—black and turkey. Kingfishers."

"Tons of kingfishers," Bolton added. "You don't see kingfishers around here. Every one of them must live in the river. You can't go 10 feet without seeing one. Herons, egrets. Amazing. Amazing. Red-winged black birds."

"And you know," Hutchinson said, "at some point in the year, there have to be bald eagles on that river."

"Night herons."

"We chased ducks for miles."

They saw one coyote. They saw countless tracks left by feral hogs but no hogs. While the hogs were shy, the beaver were gregarious. Hundreds of them came rushing out of dens in the river bank to watch the strange creatures pass by on yellow boats.

The two men camped in jungle hammocks hung from the trees above the banks, protected by mosquito netting from thick clouds of voracious mosquitoes that swarmed over them as soon as they left the water.

They pulled a few nerdy tech-tricks, like texting to a friend the GPS coordinates for a bridge they would pass later that day. When they arrived at the location, a small cooler full of ice and two frosty beers had been left there for them in honor of their journey.

At the end, they knew they had accomplished something real, Bolton said. "When we came out of the river, we both felt like telling somebody what we had just done. But we realized when we told them, they wouldn't actually understand it."

I asked them if they felt like explorers.

"I felt that way the entire time," Bolton said. "An urban explorer. Because no one ever goes down there."

Hutchinson was hesitant about the explorer thing. "People have done sections of river," he said. "But we did do the whole thing."

"It was almost a rediscovery of the river," Bolton said. "It's amazing that there's so much crap in this river. There's plastic everywhere. But still, even with all that stuff it's almost the best adventure you can get."

"The best," Hutchinson said.

"What else can you do to be by yourself alone that's kind of out there and kind of like adventurous?" Bolton said. "There's really nothing else. It's one of the biggest adventures you can have in DFW if not the biggest."

Of course by now you are asking: What about the water? E. coli, after all, isn't really a joke. And what about toxic chemicals?

It's a more tangled web than you might expect.

First off, the best reference I can steer you toward for dirty streams and lakes is the Texas Commission on Environmental Quality's list of impaired bodies of water. Just Google "Draft 2010 Texas Index of Water Quality Impairments." If you search the list for "Trinity," you will find that the Upper Trinity River in Dallas has serious issues including bacteria, chlordane and PCBs. The West Fork where Bolton and Hutchinson kayaked isn't much better.

White Rock Creek isn't on the list, nor is Rowlett Creek, which runs from Collin County down to Lake Ray Hubbard—another very pretty stream I have investigated by kayak.

But Ken Kramer, director of the Sierra Club of Texas, says you have to be careful not to take the TCEQ list as permission to dive in without your nose plugs. He says the number of water quality monitoring stations in Texas is few, so some streams may not be on the bad water list simply because they are not measured.

"As you might imagine, if you don't look for a problem, you won't find a problem," Kramer said.

Kramer pointed out that bacteria are everywhere and some evidence of bacteria in water—as from the feces of wild animals—is not an automatic bar to all recreational uses. He also explained that there is a substantial upside to people taking a chance on going out there.

The state allows lower standards—that is, it allows more pollution—in streams where there is no evidence of recreational use. Kramer said if TCEQ finds that nobody ever goes into a stream anyway, "There is a higher than average chance that TCEQ will lower the standards" for that stream.

I asked him about Hutchinson and Bolton. By going out there, taking chances and just doing it, are they then blazing a kind of legal and regulatory trail for the rest of us? Won't they and people like them establish recreational activity on a stream, forcing the state to clean it up?

"Absolutely," Kramer said. "If they survive."

This is not to detract from what Bolton and Hutchinson accomplished—they are true explorers, because they are daring guys who pierced the myth and found the kingdom of nature in our midst. There are, however, more experienced explorers on the Trinity River and other area streams. Randy Johnson of the Texas Discovery Garden is one. And on the Trinity, the grand master explorer, everyone would agree, is Charles Allen.

At 53, with hair below his shoulders and a handlebar moustache, Allen looks like a cross between Davy Crockett and Chingachgook, the Indian guide in James Fennimore Cooper's Last of the Mohicans. In fact he is a modest, soft-spoken careful student of the Trinity River and of river geography in general.

Allen has explored the Trinity for more than 30 years. Today on a cool morning in early May he and I are paddling down the Trinity in a 16-foot Old Town canoe, one of 19 boats he uses in his business as a river guide and outfitter—Trinity River Expeditions. We put in at 9:30 a.m. this morning at the Sylvan Avenue bridge boat ramp and will paddle to the take-out at Loop 12 (Ledbetter), a distance of about 10 river miles which, he says, we should accomplish in five hours.

Yeah. There's a reason man invented motors.

Even when we are still inside the barren downtown levee system, before we enter the Great Trinity Forest at the Corinth Street bridge, the river is powerful and broad-shouldered. Maybe because we are on it, paddling along its surface like a water bug, the river feels bigger and more important than the distant towers of downtown or even the bridges soaring overhead.

I'm in the front of the boat, where one merely paddles. He is in the back, where the steering is done. The day is overcast and mild.

Allen knows better than to believe the story about Dallas having no reason for being. The city was settled in the 1840s where several important overland trails converged at a ford over the Trinity River—an important means of communication and travel.

"There was river-boat traffic on the Trinity probably up into the 1920s," he says, seated behind me. "It was a way of moving big loads, lumber and machinery and so on. By then we were probably talking some kind of diesel power with a screw or propeller. Before that, it was paddle wheels."

I am a longtime, openly declared, way-out-of-the-closet non-fan of the fake suspension bridge. As we glide beneath its construction site, we see enormous steel members of the bridge un-erected, dormant in the mud, a monument to civic glory interruptus. All that money, and what a shame. They could have just come down here and gone for a paddle.

The river chokes down to 50 feet in width at some of the bridges, where it runs faster, then splays to twice that width and slows down. Allen tells me the water is moderately low today but good.

He is not the type to keep up with water volumes by using an iPhone app. After 30 years, he can take a glance when he's coming over the Sylvan Avenue bridge and know immediately whether he will put boats in the water or send everybody home because it's either too low or too high.

As we paddle, I ask him about a man who died in a canoe on the Trinity in July 2008. The man was not one of Allen's clients, but Allen made inquiries into the incident and spoke with the man's canoeing partner, who survived. Allen tells me the two men came to one of the old lock and dam sites built at the turn of the century in an effort to make the river navigable for large barges.

By the time they were able to get a good look at the obstacle, they were already in strong current and decided to punch through, as Bolton and Hutchinson did at the collapsed railroad trestle on the West Fork. But this roll of the dice cost one man his life.

"When in doubt," Allen says, "get out."

You can make mistakes out here and die. This is not Six Flags.

And now at Corinth Street, we pass out of the walled confines of the levee system and into the "Great Trinity Forest," an area of about 6,000 acres of land, treated historically by Dallas as a dump on unusable flood plain, much of it never settled or developed, now thickly grown in native trees and invasive species.

As part of the Trinity River project, Dallas promises to develop this area as a great urban wilderness park one day, presumably after it finds the money to mow the grass in the parks it already has. If Joseph Conrad's Kurtz is out here somewhere today, he's probably cooking meth instead of dealing in ivory tusks.

Along some stretches, the black mud banks soar up 50 feet above the river. At the tops of the banks, a wall of trees rises another 80 feet. No sound of man is here. Leaves clattering high above us sound like disembodied voices. An enormous gar—a prehistoric fish with heavy scales and long toothy jaws—rises and swirls just ahead. It's half the length of a paddle.

We slide down along limestone ledges glistening with water from springs and seeps deep in the woods. A huge heron lifts up from a log in the center of the river ahead and flaps off downriver like a visitor from Jurassic Park.

We come to the mouth of White Rock Creek where it meets the river. Allen turns the canoe up the creek so we can explore. How strange, almost sacred, to find this place where such a public feature of our lives carries its secrets back to the sea.

Allen points out "shell lenses" in the riverbanks—places where Native Americans camped for centuries, feasting on freshwater mussels and creating huge mounds of discarded shells, the faintest outlines of which now appear in the eroding banks.

There are far fewer plastic bags the farther from downtown we go, although they bloom again after every bridge. Allen tells me he sometimes looks at long rows of bags flying in the breeze on the tips of branches and thinks of Tibetan prayer flags.

I wonder. Getting rid of the bags, cleaning up the chemical runoff from lawns, pulling out the junk: all of those are only decisions. Acts of will. What if we did it? What if we do it? What will this river be then?

I ask him if he ever canoes on rivers other than the Trinity.

"I did back in the '90s," he says, "when I was doing a lot of white-water canoeing. Then I realized I was spending too much time canoeing and not enough time on my guide business."

We paddle along in silence for a while. Behind me at the stern he says, "I think it's important to explore other rivers. It gives you an even deeper understanding of your home river."

Tell me about it. I'm not sure I even understood I had a home river until today.

I wanted to see what the answer was: What would the main stem of the Trinity just below downtown Dallas look like if it were cleaned up? So today, a warmer day in mid-May, we are kayaking the Elm Fork of the Trinity River through an undeveloped and pristine area from just below the dam at Lake Ray Roberts, about 40 miles northwest of downtown Dallas, to a point five river miles south of where we started.

With me in another kayak is Ed Spencer, one of the best unpaid hunting and fishing guides in North Texas. You have to know him.

The descendant of many generations of North Texas hunters and fishermen including an Olympic rifleman, Spencer is also a former spokesperson for the Dallas Police Department and the Dallas County Sheriff. A big man with an easy smile that should not be mistaken for innocence, Spencer is what I would call the ultimate casual-attitude anti-REI outdoorsman.

Today, for example, I have shown up with various expensive water containers and dry bags from multiple high-end hiking and paddling outlets, not to mention a four-piece packable emergency kayak paddle for which I spent a pretty penny. Spencer, on the other hand, tossed a bunch of junk in the bottom of his boat, bungeed a big old ugly beer cooler to the deck and paddled off ahead of me, happy as a clam.

Sometimes I don't think Spencer takes the outdoors seriously enough.

There he is cruising through overhanging branches, deftly steering through small rapids, keen eye all around. And we are definitely in paradise. So this is what it could be.

The day was hot when we were putting in, but down here beneath the canopy the breeze is cool and sweet with the scent of honeysuckle. Gigantic gar turn and splash in the water just ahead of us around every bend in the river. Ducks wait until we're almost on them and then fly from low branches.

This is not at all like those rivers in Arkansas where I have paddled between soaring cliffs and nothing like the little rivers I grew up on in Michigan, silver paths through sand and pine. The Trinity River here is a tunnel through a dense forest of cedar elm, American elm, willow oak, Southern red oak, white oak, black willow, cottonwood, red ash, sycamore, pecan and bois d'arc. Every bird species in the region has flown here for respite from the hot plains above. And what really takes my breath away is the realization that this natural realm—rich, not poor, beautiful, not plain, wild, not tame—reaches into the center of our city.

Speaking of wild, there he is again, just ahead—Brother Water Moccasin. But this one is much bigger than his cousin—the one I saw on White Rock Creek a few weeks ago. And he's not happy. He swims with a bit of thrash, head well up out of the water, one glittering eye fixed dead on us. He's spring-loaded for action.

He pulls himself up on a low branch watching us warily. I know what that branch is for. It's like Donny Hutchinson's paddle. Brother Water Moccasin can take that long bicep of a body, use the branch for leverage and fling himself right across the water at me if he wants. And by the way, how did Brother Spencer get so far back behind me all of a sudden?

I don't speak snake. Can't stop now. It's all body language from here on out. I paddle very softly and sweetly. My body language is saying, "Greetings and peace, Brother Water Moccasin. We wish you good hunting."

The snake drops his head slightly. I think he has just said, "Greetings and peace, Brother Loud Slow Creature Who Walks with Dogs. I grant you safe passage on your journey back to the land of cages."

Now we're past him. And now it's easier, somehow, to go back to my land of cages. Now that I know this wild place is mine, too.