There's a word for the emotion one feels when bringing 18,000 tons of corn and soybeans into a tricky bend in the Mississippi River, knowing that wrong moves have led even experienced river captains directly onto the bank.

It's called fear.

For parts of two days, Capt. Garron Sneed of the towboat D. Ray Miller, owned by American Commercial Barge Lines, had allowed me to push a three-football-field-long tow of barges along easy stretches of the Upper Mississippi. Then he decided it was time for my final exam. This bend, he explained, was one of the many reasons that captains and pilots must know the river's personality as well as they know their own families.

He gave me a full briefing in advance on how to handle the tow. And I knew the 20-year veteran was right behind me, even if he pretended to be sitting and chatting at the back of the wheelhouse.

Palms sweating, the steering levers gripped in my hand, I made it and rumbled straight down the channel into a beautiful hazy sunset. I, who had steered nothing larger than a 24-foot sailboat, was suddenly a son of Mark Twain.

My voyage among the barges reminded me, among other things, that commerce isn't just the Internet. Commerce, still, is largely getting things from one place to another, and reports of its demise, to paraphrase Twain, are greatly exaggerated.

More than 100 million tons of bulk commodities travel down the Upper Mississippi River yearly, including $18 billion a year worth of grain for export--63 percent of all U.S. grain exports. Barge rates are so low that there is simply no rail competition from the Midwest's grain belt to the port of New Orleans. If all grain were forced to switch to rail, exports would be likely to dry up, according to the farm industry.

The barge industry is almost stealth transportation. Even in river towns, people watch the tows come and go with little thought for the economics of the industry or the unusual culture aboard the towboats.

Indeed, a political battle looms over the Upper Mississippi, over whether to spend millions to again modernize and expand crumbling navigation facilities, specifically locks, on a river that is probably the cleanest, wildest and most pristine of all major navigable waterways.

The river is a heart line to the midwestern economy, but it is also an environmental gem. And now, with a 60-year-old navigation system beset by $330 million in deferred maintenance, pressure is building to do something soon.

"A battle is raging for the river," said Teri Goodmann, a historian who is the development director for the Mississippi River Museum and the National Rivers Hall of Fame in Dubuque, Iowa.

"I think what we're talking about is the reality of the environmental health of the river and the reality of the economic future of the Midwest," Goodmann said.

The agriculture industry, the U.S. Army Corps of Engineers and the barge industry are among those that want modernization and expansion. Among those that don't are some of the country's largest environmental groups, including American Rivers, the Sierra Club and the Isaac Walton League.

At stake is whether to begin replacing some of the old 600-foot locks with new 1,200-foot locks that would allow river commerce to flow faster in harvest season. Congress almost certainly will deal with the issue next year.

The broader question is whether the river can serve all its masters--the environment, commerce and recreation. "I don't think there is an answer to the question, because the truth hasn't been discovered yet," Goodmann said.

Unlike the deeper Ohio River and the wide Lower Mississippi, commerce on the rugged Upper Mississippi, above St. Louis, had nearly vanished a century ago because its 4 1/2-foot-deep channel was inadequate for efficient freight transportation and the passenger train had all but killed the steamboat.

A six-foot channel authorized by Congress in 1907 did nothing to bring back river commerce, and by 1925 it was rare to find a vessel on the river larger than a fishing boat or a pleasure craft.

In 1930, Congress decided to tackle one of the largest public works projects in the country's history. Between 1930 and 1940, the U.S. Army Corps of Engineers built 29 locks and dams along 669 miles of river from Minneapolis to St. Louis.

With typical human arrogance, engineers and river commissions have believed for more than a century that dams and navigation aids could bring the Mississippi to heel. But, as Twain once said, "ten thousand river commissions cannot tame that lawless stream."

A towboat on the river has a crew of 10--a captain, a pilot, an engineer, a cook, two lead deckhands (sometimes called mates) and four deckhands. Except for the cook and the engineer, each crew member works 12 hours a day, seven days a week in watches--six on, six off, six on, six off. For example, Sneed handles the wheelhouse 6 a.m. to noon and 6 p.m. to midnight with pilot Terry Wedding on duty the other times.

In general, a crew member works 30 days straight, then has 20 days off. Some are regularly assigned to one boat, and some go from boat to boat as needed.

The Miller is "owned" by its "high captain," Robert Enlow, who was home while Sneed handled the regular relief-captain job, and by lead deckhand Gerald Shreve, who has been on the Miller for 14 years.

Shreve's father was a chief engineer, and four of his brothers also work for American Commercial Barge Lines. "The whole family's water people," said the veteran deckhand, who sometimes works out with weights after a hard watch of lugging steel cable about the decks as he and his crew separate the 1,200-foot tows to double through the 600-foot locks.

"It's his boat," Sneed said. "He owns it like he owns his own car--a car he thinks a lot of." He acknowledged that Shreve did a little touch-up painting on his own when he learned a reporter was going to visit.

Shreve, well, likes to talk. It's part of his job in a way, standing out on the head of the tow to talk Sneed or Wedding into a narrow lock with a cacophony of radio chatter: "Twenty wide! Twenty wide! Twenty wide! She's coming out now! You're past the bull's-eye! Five wide! Five wide!"

At Lock 16 at Muscatine, Iowa, Shreve gave his verdict of the captain's performance: "I'm kind of impressed. That's skilled labor there." He then launched into an enthusiastic radio stand-up about other captains he's worked with and how they excelled or screwed up.

"Gerrrrrrallllld," Sneed growled into the deck speakers to remind him there was work ahead.

The environmental battle is not a classic build-or-don't-build situation. Everyone agrees that the environmental beauty of the Upper Mississippi must have a place at the table beside agricultural interests. The question is how the river environment can be preserved, and even enhanced, while still building the locks and improving other facilities.

The Corps of Engineers says it can be done. The environmental movement doesn't think so.

The agricultural community, led by the Midwest Area River Coalition 2000 (MARC 2000), says that agricultural exports will suffer if something is not done soon. The National Corn Growers Association asserts that lock delays cost farmers $83.6 million in 1997.

Thomas A. Allegretti, president of the American Waterways Operators, said barges are not a source of major pollution, and so the battle is more a question of "what we want the river to be and what we want it to do."

Environmentalists, however, say the problem with barges is that they wash silt into side channels and marshes and grind up fish as they move along.

Allegretti also said he is struck by the difference between local attitudes on the Upper Mississippi and on the Ohio River, which already has 1,200-foot locks and widespread community support of river commerce.

"It's an interesting picture of national sentiment and how it varies from region to region," Allegretti said.

Yet the men and women who ply both rivers say the Ohio has paid a price: It is dirty while the Upper Mississippi is clean. Most would rather navigate the Ohio, with its modern locks and superior navigation aids. But they prefer the beauty of the Mississippi.

Scott Whitney, a biologist with the Corps of Engineers' environmental analysis branch, said the Corps' environmental analysis of the Upper Mississippi basin is "landmark in terms of its level of detail." Environmental groups "don't necessarily present all the facts" in making their arguments, he said.

Whitney also pointed out that 90 percent of the current impact on the river system is beyond the Corps' control--sediment from agricultural runoff and pollution from communities along the bank being the major problems.

"The Corps is not the ultimate evil on the river," he said.

The greatest damage on the river, he said, is on the lower mileage from about Cairo, Ill., to north of St. Louis, where 80 percent of the flood plain has been lost to agriculture. Some species of wildlife have been lost there, he said.

"We no longer support the diverse critters we once did," he said.

Conversely, the far upper river, north from about Dubuque to St. Paul, is undergoing "habitat modification" but is holding its own. It is the middle section--from Dubuque south to somewhere beyond Mark Twain's old home in Hannibal, Mo., that is undergoing "habitat degradation," he said, and most in need of environmental rehabilitation.

The problem in this middle section is that backwaters and side channels are filling up with silt and gradually losing ability to support marsh grasses and fish spawning. The Corps is putting its greatest effort into this area: habitat rehabilitation, including large dam "drawdowns" to mimmick the floods that once scoured out backwaters, side channels and sloughs.

Scott Faber, senior director of policy for American Rivers, said the Corps' programs cannot keep up. Habitat is being lost faster than it can be replaced. "It's like building a dam to create a lava flow," he said.

Faber and several agricultural-state academics take issue with projections of major increases in agricultural shipments along the river in the next century, made by the Corps and agricultural interests. Figures developed by Phil Baumel of Iowa State University indicate that traffic may well be flat for many years.

Faber said there are other ways to increase farmer income, including processing the grain near the farm and shipping high-value products rather than bulk grains. Barges, Faber said, accelerate loss of habitat, and more barges would do more damage. They push sediment into side channels, destroy marsh plants and kill fish.

The Miller operates under strict environmental rules, as do all Upper Mississippi towboats. They must keep records of trash and waste oil, which must be turned in at approved points. Trash can be burned below Dubuque, but not above.

"I've noticed the river's a lot cleaner, too," Wedding said. "Look at those banks. You don't see trash along the river. You do see more wildlife, especially deer."

The word "deer" is magic aboard the Miller. Almost everyone's a hunter. The only movement on the bank that created more excitement--and binoculars--than a bikini-clad sunbather on an unusually warm afternoon at the start of my trip was a six-point buck that wandered along the bank at dusk, almost taunting the crew.

"She's a shooter," sighed Sneed, a bow hunter and a rifle hunter who keeps a stack of hunting magazines in the wheelhouse.

After a while in the journey, I began to notice the wildlife--deer, ducks, pelicans, smaller birds and river critters that I couldn't name, making me wish I knew more about wildlife. My favorites became the pelicans. They are an ungainly bird, so disorganized that they can't form a real "V" when they migrate by the hundreds. They seem to be in a constant struggle to fly like Canada geese, but they just can't make it.

My surreal world was jerked back to reality on the second day of my three-day trip when Sneed motioned to me and said, "Here, you take it." He meant it. I was supposed to steer the towboat and its 18,000 tons of cargo along an easy stretch of river, armed only with a river chart, semi-familiar navigation aids, and two days of close observation of Sneed and Wedding.

Steering a tow is not easy. It responds slowly, and once turning it wants to keep turning. To go straight it is necessary to apply reverse rudder and "check the swing."

On the third day, he gave me the boat again, this time with more curves and with a channel that made several transitions from one bank to the other. I noticed the sharp bend at Long Island, on the chart, but didn't think much of it till Sneed began giving me a serious briefing.

This is a tough bend, he said. Even an experienced captain can misjudge this bend, especially if the currents shift from the last trip. And novice pilots have rammed their tows right up on the far bank.

Do what feels right here, he said, and everything will go wrong. Resist the inevitable urge to hug the inside of the bend because you'll find yourself "boxing the curve," or needing to turn too sharply without enough water ahead of you. Instead, cling to the outer bank, which may feel odd, then, at the right moment, turn like hell.

The right moment? Well, I'm supposed to figure that out.

I tried to follow his instructions exactly. At only one point did he need to correct me. "Shape out your bend," he said, meaning get closer to the outside bank. I thought I was close to the outside bank.

Like the captain in Joseph Conrad's "The Secret Sharer," my adrenaline began pumping as I wondered where to begin my turn. My hand began gripping the sticks--the steering levers--as the hill on the outer bank, now directly ahead of me, drew closer.

After my emotions told me I had waited too late, I waited another few seconds and began nudging the sticks toward full right rudder. A split second later, Sneed, peering ahead, said, "Okay, begin your turn." I had begun it. My judgment was his judgment. Talk about proud.

"Give your port engine a little power," Sneed said. That would aid in the turn. I pushed the throttle lever forward and could feel the rumble through the seat of my pants. It was a reassuring vibration.

As soon as I knew I would not churn up the bank, I began checking my swing, easing the tow into the middle of the channel and heading into a dusky sunset.

"That was good, that was good," Sneed said.

Later, as Sneed and I watched the sunset turn into a rosy backdrop to the lights of the Quad Cities, we agreed the wheelhouse of a towboat is a good place.

"I work six months a year," Sneed said. "I eat three meals a day. I watch pretty sunsets. I been everywhere. And they pay me for it."