Throughout its 2,340-mi. course down through the middle of the United States, the Mississippi River is spanned by bridges, which have become part of the river’s saga.
Native Americans and fur traders traveled the river by canoe. Abe Lincoln brought meat and corn to New Orleans by flatboat in the 1820s. By 1857, more than 1,000 steamboats plied the waters in lucrative trade, a time that author Mark Twain wrote about vividly.
Crossing the Mississippi, especially where it was more than a half mile wide, was always a problem. Westward-bound pioneers used ferries until after the Civil War. Then, spurred by the needs of new railroad transportation, bridges began to be built —usually structures that swung in the middle to let boats through.
The first major bridge over the Mississippi was the Eads Bridge in St. Louis, built in 1874 for railroads. In almost-continuous use since then, this magnificent fixed structure currently is being rehabbed for vehicular traffic as well as the regular light rail system.
As roadways grew in the developing nation, and as automobiles appeared and multiplied, bridges had to accommodate motorists. New ones were built over the “Mighty Miss” throughout the 20th century, especially in the 1920s and 1930s to meet the needs of motorists.
“A lot of bridges over the river, had to be rebuilt and widened in that era because of new roads and wider cars or trucks,” said Roger Wiebusch, bridge administrator of the U.S. Coast Guard in St. Louis, MO.
The Coast Guard is responsible for commercial navigable waters on the Mississippi all the way from New Orleans to the Twin Cities in Minnesota, including the numerous locks and dams from St. Louis to Minneapolis/St. Paul. The channel must be at least 9 ft. deep.
Many of the 1920s- to 1930s-era bridges have been rebuilt or replaced as bridge technology has improved, making it easier to construct longer spans. Now graceful cable-stayed structures stretch 2,000 ft. or more over the river which Lincoln and Twain saw as unbroken vistas.
Here’s an overview of the Mississippi and its bridges, circa 2003, and some of the plans for the future.
Across the Great River
Native Americans called it Missi Sipi or “Great River.” At first, the Mississippi begins as a small, clear stream flowing northward from Lake Itasca, 1,467 ft. above sea level, in northwestern Minnesota, fewer than 200 mi. from the Canadian border.
“As the river flows from the lake, it can be waded across,” said Dan Dorgan, state bridge engineer, of the Minnesota Department of Transportation (MNDOT).
After turning eastward, the waters curve southward at Grand Rapids, MN. It soon becomes a wide river, the fabled Mighty Mississippi, which passes through Minnesota and nine more states — Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi and Louisiana — before flowing into the Gulf of Mexico below New Orleans, LA.
Spanning the broad waters with safe bridges, which meet growing capacity demands, is a high priority in all 10 states bordering the river. One can see many types of bridges on the Mississippi. The large new ones are often “cable-stayed” designs, building out from towers at each end, rather than requiring more-expensive temporary structures to support the deck.
MNDOT has 20 bridges over the main channel, including six that it co-owns with Wisconsin. The river bridges are large projects. The state has replaced or rebuilt at least 14-trunk highway or county/city Mississippi bridges during the past 20 years. It is currently reconstructing or replacing three bridges in the Twin Cities and plans to build more.
“We expect that the Lafayette Bridge in St. Paul and the I-90 interstate crossing southeast of Winona will need replacement or reconstruction in about 10 years,” Dorgan said.
South of the Twin Cities, the Mississippi forms part of the Minnesota/Wisconsin border. At Lake Pepin, in Southeastern Minnesota, it is more than 2 mi. wide.
Wisconsin and Minnesota
Wisconsin and Minnesota share six bridges along more than 100 mi. of waterway.
“The bridges average about 40 mi. apart and usage is very high because they’re the only way across for commercial, commuter and pleasure purposes,” said Bruce Karow, chief structure maintenance engineer, of the Wisconsin DOT in Madison. “I’d say, they are a very important resource and an important part of the history and culture of our state. We intend to maintain them as close to new construction [condition] as possible.”
Wisconsin also is building a new four-lane bridge, which it will own completely, from La Crosse to an island in the river. This will supplement an existing two-lane bridge.
Further downriver, the river also forms part of the Iowa/Wisconsin border, with the two states sharing ownership of three bridges — at Marquette, Dubuque and Lansing, IA.
Next, the river forms the border of Iowa and Illinois. Bridges between these states include a second bridge at Dubuque, plus the I-80 bridge east of Bettendorf, two bridges at Davenport, IA, four south of Davenport, and two in Clinton. There also are three other bridges, which are private toll facilities, between the states.
“Tying in river crossings with urban centers is quite a challenge,” said Dan Franklin, director, of the Office of Policy and Legislative Services of the Iowa Department of Transportation (IADOT) in Ames.
“One of the things we’re looking at for future needs is the cost of major river structures. We have major studies going on to replace or rehab quite a few of our existing bridges.”
IADOT is studying the feasibility of an additional two-lane bridge next to the existing U.S. 20 bridge (shared with Illinois) at Dubuque. Design work is under way on this $170-million project.
To handle more traffic capacity, Iowa also is discussing a new six-lane bridge carrying I-74 from Bettendorf, IA, to Moline, IL. This would be built next to the present I-74 bridge.
Cost estimates for the I-74 project, including roadway, are approximately $600 million, with the bridge itself costing about $200 million, Franklin told Construction Equipment Guide (CEG).
According to Dale VanderSchaaf, executive officer, of IADOT, “The I-74 project is a ways down the lane, at least 2008 to 2009 at the earliest.”
A study also has identified a long-range need (by 2020 or 2024) for a new bridge between the I-80 and I-74 spans.
The Mississippi next forms the border between Illinois and Missouri. In northern Missouri, it sweeps past Hannibal, MO, Mark Twain’s boyhood home. Then, above St. Louis, two major tributaries, the Illinois River and the Missouri River, join the river, giving it a muddy color.
Illinois and Missouri
Seventeen bridges now carry traffic between Illinois and Missouri, beginning with a cable-stayed bridge at Quincy in the north and ending with two bridges at Cairo, IL.
At Hannibal, near where Huck Finn paddled the river, a new truss bridge, 4,500 ft. long (including spans) carries the I-72 and U.S. 36 highways.
Then, continuing downriver, a traveler goes under the Louisiana Bridge south of Hannibal; a cable-stayed bridge at Alton, north of St. Louis; the Chain of Rocks Bridge on the north edge of St. Louis; the closed McKinley Bridge, originally built for railroads; the Martin Luther King Bridge, in St. Louis; and then the famed Eads Bridge.
By late 2003, the Eads Bridge, being reconstructed, is expected to be open again, this time carrying traffic as well as the Metrolink light rail line between St. Louis, MO, and East St. Louis in Illinois.
South of Eads, the Poplar St. Bridge carries the heaviest bridge traffic in the state on I-55, I-70 and I-64. A major new bridge, in the planning stage, will alleviate this capacity problem. To be located between the McKinley and MLK bridges, it will carry I-70 and some of the other traffic across the longest clearspan cable-stayed bridge in the United States, with more than 2,000 ft. between columns.
“If built as conceived, the new river bridge would be about 222 ft. wide, making it the widest bridge over the Mississippi,” said Bob Brendel, outreach coordinator of project development, of the Missouri DOT in Jefferson City, MO.
“We expect a big spaghetti bowl of interchanges on each side, allowing motorists to get from one structure to another,” said Carl Callahan, state bridge maintenance engineer, of MODOT. “We’re looking at probably $1 billion in total costs.”
Illinois would be the lead agency on this new bridge, with Missouri contributing approximately $350 million. Proposals call for the new bridge to be ready in 10 years.
The Mississippi is “open water” from St. Louis south, with no major locks and dams.
South of St. Louis
South of St. Louis, a traveler passes under the two I-255 Jefferson Barracks “tied arch” (having a structural support across the bottom of the arch design) bridges, the old Chester Toll Bridge, and then the Cape Girardeau Bridge, connecting U.S. 36 in Missouri with I-72 in Illinois, approximately 100 mi. south of St. Louis. This bridge is to be replaced by the new Emerson Bridge in fall 2003.
There are the last two bridges between Missouri and Illinois at Cairo, IL, and a bridge from Missouri to Tennessee at Carruthersville, MO.
Kentucky has only a short border with the Mississippi but it, too, shares a bridge over the waters. This is the U.S. 51 span from Wickliffe, KY, across the confluence of the Mississippi and Ohio Rivers to Cairo, IL. Kentucky also boasts new cable-stayed bridges on the Ohio River.
When the Ohio River flows into the Mississippi at Cairo, it doubles the river’s volume of water.
Arkansas, Mississippi and Tennessee
As it curves and flows further south, the river forms the Eastern Arkansas border with Tennessee and Mississippi and more bridges appear. In the north, the I-40 and I-55 bridges, connect Memphis, TN, and Arkansas.
A massive “seismic retrofitting” project is under way to protect the I-40 span against earthquakes. This seven-year undertaking, now in its third year, will cost an estimated $200-million, with Tennessee paying 60 percent.
The next major bridge downriver is the U.S. 49 connecting Helena, AR and Mississippi.
Then, approximately 30 mi. north of Greenville, there’s an area with great plans. A new “Great River Bridge” is to carry a new I-69 corridor between Arkansas and Mississippi on the highway’s anticipated course from Indiana to Texas.
Further downriver, another span carries U.S. 82 over the waters between Greenville, MS, and Chicot County, AR. This bridge is doomed. It will be replaced with a new cable-stayed span being built. Approach-spans contracts will be let shortly for this 1,400-ft. bridge scheduled to be completed September, 2005.
South from Greenville, the I-20 Bridge connects Vicksburg, MS, and Tallulah, LA and the U.S. 84 Bridge connects Natchez, MS, and Vidalia, LA.
End of Journey
The Mississippi’s long, beautiful journey approaches its destination.
From north of Baton Rouge, LA, to the Gulf, it deposits large amounts of silt to form a delta covering approximately 13,000 sq. mi. Levees along its banks keep the wide river from spreading to the original flood plain.
The bridges over the river at the end of the journey are long and graceful.
Proceeding downriver, in Baton Rouge, the U.S. 190 Bridge, a cantilevered steel truss design, is 5,880 ft. long.
In West Baton Rouge, the I-10 Bridge, of the same design, is 4,550 ft. long.
The Sunshine Bridge at Donaldsonville, between Ascension and St. James parishes, opened in 1964, is 8,236 ft. long. It was named for either Gov. Jimmy Davis’ horse Sunshine, or the song he wrote, “You Are My Sunshine.” Finished before State Highway 22, it also was called “The Bridge to Nowhere.”
Between Gramercy and Wallace, LA, the Veterans Memorial Bridge, opened in 1995, is 3,014 ft. long.
At Luling, LA, the cable-stayed Hale Boggs Bridge, with a main span of 1,222 ft., won a national design award after it opened in 1983. Boggs was instrumental in obtaining highway and bridge funds for the state before disappearing in a small plane over Alaska.
The Huey P. Long Bridge, 106 mi. from the mouth of the river, opened in 1936, is still the longest combination railroad and automobile bridge in the world. This high-level cantilevered steel-truss bridge has a main suspended span of 790 ft. Its highway section is 9,364 ft. long, including approaches, and its railroad section is 22,996 ft. long.
There also are two twin bridges, each 2,711 ft. long, next to each other across the Mississippi in downtown New Orleans, which is below sea level.
The Louisiana DOT is conducting preliminary studies for a major new bridge at St. Francisville, approximately 35 mi. north of Baton Rouge. This cantilevered steel-truss structure will be built in 20 years.
After flowing through a land of plenty — and bridges — waters which have run the whole length of the country break into several channels south of New Orleans and merge with the Gulf.
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