America’s Working Waterways – Post VIII: The Missouri River
Not a Major Grain River — But Its Water Is Critical to the Middle and Lower Mississippi
The Water That Shows Up at St. Louis
Back when we ran the grain dock in St. Louis right across from Locks 27, the Missouri was part of the daily calculation even when we were not loading a barge on it. Ice came down from both the Upper Mississippi and the Missouri. Every spring the Missouri sent heavy drift; whole trees, root balls, whatever it picked up. A loaded barge sitting at the dock was a big target. We kept a kicker barge set at an angle off the upstream bank to throw that ice and drift out into the channel. One spring, before the kicker was in place, a load of drift hit the upper tower and knocked a barge loose. It went downriver on its own and hit the bridge just below the dock before a harbor boat could catch it.
The sediment does the same kind of work, only slower. Anybody who has stood on the riverfront at St. Louis knows the water below the Missouri confluence does not look like the water above it. That mud is a big part of why dredges stay busy on the Middle Mississippi. The Missouri’s stage and flow also change the current at the docks and in the harbor. Some days the river helped us; some days we had to turn the whole operation around and work against it.
That is the point of this post. The Missouri is not a major grain river. Its own commercial volumes are small. But the water, the sediment, the ice, and the drift it delivers to the Mississippi just above St. Louis are critical to how the Middle Mississippi and the Lower Mississippi actually run.
This is Post VIII of America’s Working Waterways. Towboats, barges, fleeting, and harbor work are in the companion post, How the System Actually Runs. Here we stay on the Missouri itself and on what its water does once it reaches St. Louis.
How to use this post: Read it once for the operating picture. Come back for the numbers when you need to compare it with the Illinois or the Upper Mississippi, or when you are watching the St. Louis gauge.
What This Corridor Is
The Missouri runs more than 2,300 miles from the Rockies to the Mississippi. For most of its history it was a free-running, shifting river that carried steamboats in the 19th century but offered no reliable channel for modern commercial barges. The commercial navigation project that exists today covers the lower 735 miles, from Sioux City, Iowa, to the mouth just above St. Louis.
There are no locks on that stretch. The channel is authorized at 9 feet deep and 300 feet wide under the Rivers and Harbors Act of 1945. The Corps holds it with the Bank Stabilization and Navigation Project, using dikes set perpendicular to the flow and revetments along the banks, so the river scours its own bed rather than relying on continuous dredging. Construction of the project was completed in the early 1980s. Maintenance of the structures continues.
Above Sioux City the river is controlled by six mainstem dams and reservoirs built primarily for flood control, irrigation, hydropower, water supply, and recreation. Navigation was an authorized purpose, but it was never the dominant one. Commercial barges do not transit those dams. Navigation flow support is released from the system, primarily from Gavins Point, the lowest dam.
Full-service flows target the 9-foot channel. Minimum-service flows support about 8 feet. Season length and service level are set by system storage checks, usually mid-March and early July. In a normal year the window runs from late March into early December. In dry years it shortens and the flows drop. That multi-purpose reservoir system is why the navigation season cannot be treated as fixed.
The river joins the Mississippi just above St. Louis. Technically that confluence is the start of the Middle Mississippi. In practice a barge leaving the Missouri still has to pass Locks 27, the last lock on the Mississippi and part of the Upper system, to reach the open river below. The Chain of Rocks reach in the main channel is a series of rock ledges that become unnavigable at low water; the 8.4-mile Chain of Rocks Canal and Locks 27 (opened 1953) were built to bypass it. Locks 27 is the only lock south of the confluence. Clearing it is the practical entry into the Middle Mississippi and the St. Louis harbor. Everything that leaves the Missouri, cargo or just water and sediment, enters the system at that point and affects the harbor, the open river to Cairo, and the Lower Mississippi below.
What Moves on the Missouri Itself
Sand and gravel dominate. Recent annual totals have run on the order of 4.5 to 5.5 million tons. Most of that is sand, gravel, and waterway materials. Long-haul commercial tonnage is far smaller, often under 500,000 to 800,000 tons.
Grain is a minor share of even that smaller number. Corn, soybeans, and wheat together have typically moved in the tens of thousands to a couple hundred thousand tons in a given year. Fertilizer moves inbound in limited but more consistent volumes. In practice, the grain that does load often serves as a backhaul to the fertilizer that came up. These figures come from Corps waterborne commerce data and annual navigation summaries. Treat any single year as a reading of that season’s flows and demand.
It was not always this thin. In the 1960s and early 1970s grain volumes were higher. Wheat and other farm products made up a larger share of commercial traffic in some years. Traffic peaked near 3 million tons of commercial cargo in the late 1970s and then declined. By the early 2000s long-haul commercial tonnage had fallen well below earlier levels, and sand and gravel had become the dominant cargo. The decline tracks the growth of shuttle rail, the rise of processor demand closer to the farm, and the simple fact that the Missouri’s navigation window has never been as reliable as the pooled rivers farther east.
The pattern is consistent. The Missouri carries well under 2 percent of the grain produced in the states it touches. A standard hopper barge at 9 feet still holds roughly 1,500 short tons, but that arithmetic only matters on the days the channel and the flows actually allow the draft. Most of the region’s grain never sees a Missouri River barge.
How It Runs
There is no lock staircase. A tow that can make the draft and the current runs the open river. The authorized 9 feet is a target under full navigation service, not a guarantee. Minimum-service flows support a shallower channel. Even under full service, crossings can be shallow; operators have reported bottoming downstream of Kansas City when target flows are being met. Velocities run higher than on the pooled rivers.
The season is the other clock. In dry years the Corps reduces releases to conserve water for the other authorized purposes of the system. Usable draft falls with the flows. High water brings its own restrictions. The result is a navigation window that is shorter and less predictable than the open-water months on the Illinois or the Middle Mississippi.
Because the volumes are low, the equipment cycle is thin. Empties have to come up for fertilizer or other inbound cargo before they can load grain. A disruption on the Mississippi below St. Louis tightens that cycle further. The same river that supplies the water also supplies the constraints that keep most grain on rail or truck.
The Bank Stabilization and Navigation Project was designed to create a self-scouring channel so that continuous dredging would not be required. It works when the flows are adequate. When they are not, or when sediment from tributaries and the main stem shifts the crossings, the channel still needs attention. The structures themselves require ongoing maintenance. That is ordinary river work, not a one-time fix.
Where Cargo Gets On
Terminals and docks exist along the reach in areas around Sioux City, Omaha, the Kansas City, and points lower. Some handle fertilizer, petroleum, aggregates, or occasional grain. Ownership and activity change. What matters is that the facilities serve the cargo that actually moves, and that most of the region’s grain moves by rail or truck instead.
A house that can load a barge still needs empties, a workable draft, a season that is still open, and a rate that beats the alternatives. On the Missouri those conditions line up less often than they do on the Illinois or the Upper Mississippi. The docks that stay busy are more often moving fertilizer, petroleum, or local aggregates than building the long grain tows that define the main-stem rivers.
Most of the older grain houses either closed their barge operations or reduced them to occasional loads once shuttle rail and local processors expanded.
What Stops It — and What It Does to St. Louis
Demand is not the limit on the Missouri itself. Hydrology, season length, and location are.
Low system storage cuts navigation flow support. The channel may stay open on paper while usable draft falls below what a loaded grain barge needs. High water and strong current restrict or stop movement. Localized shoaling at crossings requires lighter loads or waiting. The training structures need ongoing maintenance.
The larger effect shows up at St. Louis and below. The Missouri delivers a heavy sediment load. That mud is a primary reason dredges stay busy on the Middle Mississippi. Ice and drift from the Missouri reach the St. Louis harbor and the docks below Lock 27 every winter and spring. Stage and flow from the Missouri change the current in the harbor; operators who load there learn when the river sets one way and when it sets the other. In high-water years the Missouri’s contribution helps drive the gauge at St. Louis. When that gauge goes over 38 feet, traffic through the harbor stops. In low-water years the reduced flow from the Missouri is part of the stage picture that forces draft cuts and smaller tows on the Middle and Lower Mississippi.
The 1993 flood made the point on a scale no one had seen. Navigation on both the Missouri and the Mississippi was closed from early July. The Missouri set new crests from Kansas City downstream; 48.9 feet at Kansas City on July 27, then records at Boonville, Jefferson City, Hermann, and St. Charles. That water joined an already high Mississippi and drove the St. Louis gauge to 49.58 feet on August 1, more than six feet above the previous record. The river stayed above the old record for three weeks. At St. Charles the Missouri was above flood stage for 94 days. Nearly all of the roughly 700 privately built agricultural levees on the lower Missouri were overtopped or destroyed.
Sediment came with the water. USGS measurements showed the Missouri at Hermann moving on the order of 70 million metric tons of suspended sediment during the flood period, roughly ten times the load on the Mississippi below Grafton. Some of that material settled in the floodplain between Hermann and the mouth; more kept moving past St. Louis. Barge traffic was stopped for nearly two months. The loss in commerce was estimated at about $2 million a day in 1993 dollars. The Missouri was not loading grain. It was delivering the water and the mud that shut the harbor and the open river below it.
Those effects are not new. The same confluence that made St. Louis a river town in the steamboat era still shapes the modern harbor. The kicker barge we used for ice and drift was a practical answer to a problem the Missouri has delivered for generations. The sediment load that keeps dredges working on the Middle Mississippi is the same load that made the unregulated river difficult to navigate before the dams and the Bank Stabilization project. The difference is that the modern system manages the water for multiple purposes. Navigation receives what is left after the other authorized uses are considered.
The Missouri is not moving the grain. Its water, sediment, ice, and drift are shaping the river that does.
What Else Can Take the Grain
Rail is the primary alternative for most grain in the Missouri River states. Shuttle loaders, processor bids, and direct moves to the Pacific Northwest or the Gulf do not wait on a storage check or a shallow crossing. Truck handles the first miles. Storage lets a house wait.
The river can still be the right door on the days the flows, the draft, and the empties line up, especially for fertilizer inbound and for grain that can ride as a backhaul. Those days are not the majority of the marketing year. For the bulk of the crop, the Missouri is an option, not the path.
That shift has been underway for decades. The growth of unit trains and local ethanol and crush plants gave producers outlets that do not depend on a variable navigation season. The Missouri still offers a water option when conditions cooperate. It does not set the basis for most of the grain grown in its basin the way the Illinois or the Upper Mississippi do for theirs.
What Has to Change
On the Missouri itself, the practical work is keeping the training structures maintained and publishing clear notice on service level and season length. A longer or deeper season would require different reservoir priorities. That is a multi-purpose water decision, not a simple navigation fix.
For the larger system, the Missouri’s contribution of water and sediment has to be managed as part of Middle and Lower Mississippi operations. Dredging plans, harbor restrictions at St. Louis, and low-water responses on the open river all feel the Missouri whether or not a single grain barge loaded on it that week.
The history of the river shows both the capability that was built and the limits that were never removed. The 1945 authorization and the Bank Stabilization project created a workable channel. The multi-purpose dams and the competing demands on the water supply kept that channel from becoming a high-volume, high-reliability grain route. Those constraints remain.
Operator’s Scorecard
Measure | Missouri River |
Length | ~735 miles authorized navigation, Sioux City to mouth near St. Louis |
Own cargo | Sand/gravel dominant; limited long-haul commercial; small grain volumes; fertilizer inbound |
Channel | 9 ft × 300 ft authorized under full service; open river, no locks; held by dikes and revetments |
Season | Typically late March–early December; length and service level set by system storage checks |
Effect at St. Louis | Major sediment source; ice and drift; stage and current changes in the harbor and on the Middle Mississippi |
Risk to own traffic | Short or reduced season in dry years; shallow crossings; thin equipment cycle |
Risk it creates downstream | Sediment load, ice/drift, and flow contributions that affect Middle and Lower Mississippi draft, dredging, and harbor operations |
Alternatives for its grain | Rail (Gulf, PNW, processors), truck, storage |
Strategic note | Real but limited commercial capability; not a major grain mover; its water is critical to the rivers that are |
GG50 Operator Take
The Missouri can move barges when the flows and the channel cooperate. That capability is real and it is limited. Grain volumes are small. The season is variable. Most of the crop in the states it serves already moves by rail or truck.
What the Missouri does deliver in volume is water, sediment, ice, and drift. Those show up at St. Louis every year. They help set the gauge, the current at the docks, the dredging load on the Middle Mississippi, and the ice and drift problems in the harbor. The Missouri is not a major grain river. Its water is still critical to the Middle and Lower Mississippi, the rivers that actually carry the grain.
Next in the series is the Lower Mississippi and the Gulf export engine, the stretch that has to absorb everything the Missouri, the Illinois, and the Upper Mississippi send it.
Thank you for reading. Feedback from elevators, processors, terminals, and anyone who watches how grain gets to market helps shape this series.
Regards,
Grain Guy Fifty
See Glossary: https://www.grainguyfifty.com/post/the-gg50-america-s-working-waterway-vocabulary-glossary-of-terms
Sources
• U.S. Army Corps of Engineers, Missouri River Basin, Kansas City District, and Omaha District: channel authorization (Rivers and Harbors Act of 1945), Bank Stabilization and Navigation Project, navigation flow support, season rules, and annual summaries.
• USACE Waterborne Commerce Statistics: tonnage by commodity, historical commercial traffic trends.
• Series Post VI (Middle Mississippi) and operator experience at St. Louis harbor: sediment, ice, drift, and current effects below the Missouri confluence.
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USDA and related reporting for Mississippi system context.
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