ON THE MISSISSIPPI RIVER - Jim Kennedy watches the river like a hawk.

From his view 33 feet up in the pilot house, Kennedy stares out wide windows at blackened driftwood, eddies, even sometimes rambunctious yachters steaming up the wide, blue waters of the Mississippi River near St. Paul.

"They're about the worst kind," Kennedy said, on the Tuesday after Labor Day. "Drunk yachters. But they can't be helped."

Another problem that can't be helped? Mother Nature's curveballs, like this year's devastating drought in America's heartland. And another trying year for U.S. agricultural exports, due to the high cost of diesel and lower commodity prices.

In a typical year, 60% of the nation's grain flows downstream to the Gulf of Mexico, loaded onto barges parked at terminals along the Mississippi River. The barges are often tucked below interstate overpasses or along remote stretches of inland waterways, noticed only by boater or beaver.

But, lately, the working river has garnered more attention as concern grows over the aging locks-and-dams system built in the Roosevelt administration. The industry has been further strained by scarce labor and whiplashing weather that at times makes navigability uncertain.

Farmers and grain buyers, including agribusiness titans in the Twin Cities, are increasingly watchful.

"On this part of the river, we're here because of ag," said Lee Nelson, president of Upper River Services. He noted an outstate farmer — say in southern Minnesota — may not want to drive all the way to downtown St. Paul to the Mississippi terminal.

"But he can get to the water [in Savage, Minn.]," Nelson said, referring to the grain terminals in the outer Twin Cities suburb sitting on the Minnesota River.

Kevin Hall, a supply chain vice president at Inver Grove Heights-based CHS, Inc., stared last week at a bank of video screens on the wall of the trading floor of the nation's largest farmer-owned cooperative at the Inver Grove Heights headquarters.

On screen were live-feeds of terminals from Savage on the Minnesota River all the way down to Myrtle Grove, La. The last major floods hit in the 1920s, prompting the U.S. government to begin damming up the Mississippi during the Depression, Hall said.

"It was catastrophic to the communities down the river," he said. "But it was to create this navigable waterway."

The river north of St. Louis — with two dozen locks and dams — is not the problem. The infrastructure there works, keeping a consistent flow for barges moving past Winona, Dubuque, Iowa, and Quincy, Ill., industry sources say.

But lack of water in the whole system could mean a repeat of last year's near-catastrophe when water levels dropped too low for steel-bottomed barges to traverse.

"When the Mississippi River had disruption last year, it was a major disruption to the country," Hall said.

Last fall, barge traffic on the southern portion of the Mississippi River — part of an intermodal system of riverways, highways and railways once the envy of the world — ground to a halt.

Television news carried images of more than 2,000 barges stuck in a queue. The U.S. Coast Guard briefly halted traffic in Memphis and Vicksburg, Miss., after boats ran aground on sandbars. An AccuWeather report estimated river snags cost the country $20 billion.

As this year's harvest begins, water levels on the storied Mississippi are once again dropping. The river is below 5-feet deep in the Quad Cities on the Iowa-Illinois border. More than 50% of Minnesota is currently in at least "severe" drought, according to a national monitor. In St. Louis, barge rates — the per-ton cost to ship on the river — are spiking.

And the row-croppers of the Upper Midwest, who need the floating vessels to carry their corn or soybeans to the world, are watching with trepidation.

"As harvest approaches, really all we can do is wait to see what happens with the river," Brad Hovel, a Cannon Falls farmer and secretary of Minnesota Soybean Growers Association, said. "We might be eating our basis."

A farmer's basis — that is, the profit farmers can make at the elevator over futures contracts posted in Chicago — could weaken if the U.S. Coast Guard imposes greater draft restrictions (how deep a boat can dip below the water's surface) to protect boats from running aground.

Hovel said farmers in his neighborhood of southeastern Minnesota can put grain on rail, often traveling up to the Twin Ports in Duluth or out to the Pacific Northwest. They might also truck grain to two crush facilities in Mankato. But the terminals along the Mississippi are vital.

"We've only got a little bit of wiggle room," Hovel said.

The challenges couldn't hit at worse time, as U.S. farmers fight to reclaim past supremacy in exports. This year, Brazilian farmers are on path to surpass U.S. corn-growers as the world's top exporter. Brazil is tops in soybean, too, overcoming supply challenges that long bedeviled the South American ag giant.

Justin Cauley, CHS' senior director of transportation, said Brazil farmers are reporting 40-day lines at some terminals.

"A [bulk] vessel sitting costs about $20 [thousand] to $30,000 a day," Cauley said. "They're able to let their vessels sit for 40 days and still be competitive against the U.S."

Those on the working river say what's needed is infrastructure upgrades. The 2021 Bipartisan Infrastructure Bill that passed Congress and was signed by President Joe Biden allocated $2.5 billion for the inland waterways. Ongoing dredging of the river — such as two low spots near Savage this past summer — is an evergreen need, as well.

But industry officials say they also need more workers interested in joining a boat.

Back in the waterways near St. Paul, Kennedy is at home on his boat. There's a fridge for long days. He arrives by 6 a.m. and often works until dark. He likes the job and sleeps each night at home in Cottage Grove. He's seen early morning fishermen, wildlife and scenes along the river that most recreationists and oil painters dream of.

Nestled between two windows, a placard dedicated to his son, Joseph Kennedy, an Army specialist who was killed in Afghanistan in 2011, reads "Some Gave All."

"He worked here," Jim said, quietly. "He was a good worker."

Out on driftwood, a bald eagle was perched, surveying the region. Kennedy says he didn't see those big birds in his first couple of decades on the river. But the waterway — and the life around the banks — keeps changing.