Post-Industrial History

Post-Industrial History of St. Louis River

Lake Superior and Mississippi Railroad

Between Riverside and Thomson are traces of the abandoned Lake Superior and Mississippi Railroad. In the 1850s and 1860s, demand grew for a rail line connecting the Mississippi River to Lake Superior to reduce transportation costs for farm products, lumber, and other commodities. The railroad was organized in 1861, but financing challenges and the Civil War delayed completion until 1870. The final spike was driven on August 1, 1870, and the first train arrived in Duluth from St. Paul that same day.

The stretch between Thomson and Riverside offered spectacular views of the river’s waterfalls and rapids, but it was also dangerous. High wooden trestles spanned deep ravines and were frequently threatened by fires from wood-burning locomotives. Steep grades and spring mudslides caused regular delays, and at least one train slid into the river. The arrival of rail service fueled rapid growth—Duluth grew from 14 families in 1869 to 3,500 people by 1870, and by 1892 the population exceeded 50,000.

Since 1980, the Lake Superior and Mississippi Railroad has operated as a tourist excursion using a portion of the original right-of-way and, in some places the original track, along the river from the Gary-New Duluth neighborhood to the Fremont neighborhood in Duluth. Learn more about LSMRR history here.

Bridges

The railroad industry developed the first bridges linking Duluth and Superior. In 1887, a railroad bridge was constructed between Grassy Point and Superior with a swing span to allow ships to pass upstream. Farther upriver, another railroad bridge, the Oliver Bridge, connected New Duluth, Minnesota, and Oliver, Wisconsin, accommodating both rail and vehicle traffic.

Logging Era

The railroads spurred new towns and industrial development, with lumber becoming one of the region’s earliest and largest industries. As the white pine forests were cut, logs were brought to saw mills on the lower river; large numbers of logs were stored in the river at Fond du Lac surrounded by floating booms, waiting to be cut into lumber at sawmills. By 1894, Duluth’s lumber industry included 15 sawmills, all located along the St. Louis River. But the boom was short-lived; by 1925 only one mill remained. The white pine forests, which in 1895 had been estimated to hold a virtually inexhaustible 40 billion feet of lumber, had largely disappeared.

Quarries

Three sandstone quarries operated near Fond du Lac—one along Mission Creek, another on the south side of the river about a mile above Fond du Lac, and another on the north side of the river. Many stately “brownstone” buildings around Duluth and the Midwest were built with this stone. During quarry operations, the shipping channel was dredged from the main harbor to Fond du Lac to facilitate transport of the rock. Quarry scars remain visible today.

Dredging

By 1960, major channels were dredged to depths of 23–27 feet, dramatically altering the once-shallow freshwater estuary. More than 69.5 million cubic yards of clay and mud mixed with sand (sediment) were removed from the river bottom, reshaping shorelines and habitats. Dredged material was used as fill to create docks, replensih eroded areas on Minnesota and Wisconsin Points, and to form new islands. The navigation channel is not marked by buoys due to constant changes in water levels.

Steel

The United States Steel Corporation (U.S. Steel) was formed in 1901, followed by its subsidiary Oliver Mining Corporation. In 1907, U.S. Steel (through its subsidiary the Minnesota Steel Company) purchased 500 acres of land along the St. Louis River in West Duluth, completing a coke production plant by 1915. The facility drove rapid growth in Gary and New Duluth. The coke produced was used for steelmaking. Coking byproducts include gas and heavy oils; the heavy oils were captured and sold, but the gas byproducts were released into the air. In 1911, Universal Portland Cement Company built a plant alongside the steel operation to use the furnace slag for cement making. The nearby community of Morgan Park was built to house the steel plant and cement plant workers. The steel facility closed in 1973 and was known as the U.S. Steel Superfund site.

In July 2024, U.S. Environmental Protection Agency announced the completion of a four-year, $186 million sediment cleanup and habitat restoration project at Spirit Lake.

Coal

In 1902, the Zenith Furnace Company began operation. It was a “three-unit” plant, which included a wholesale coal trade, the production of pig iron and the coking of bituminous coal. This site later became Interlake Iron. The coking operation at this site included the capture and sale of coking byproducts: heavy oils were sold to Duluth Tar and Chemical, and manufactured coal gas (“town gas”) was sold to the City of Duluth. This gas was piped to residences where it was burned to produce heat and light.

The 1950s saw the beginning of a steady decline in coal shipments, as it began to be replaced with other fuels. By 1959, the number of coal wharves dropped to 14. By 1970, three wharves remained. Coal is still an important commodity. Low-sulfur western coal is brought by rail to Midwest Energy Resources in Superior, where it is loaded onto ships bound for Detroit Edison power plants in Michigan.

In 1983, St. Louis River Interlake/Duluth Tar (SLRIDT) was designated a Superfund Site. The site underwent a sediment cleanup under the Minnesota Pollution Control Agency's Superfund program from 2006-2010. A Great Lakes Legacy Act (GLLA) project was performed in 2010 to improve the cleanup's effectiveness. This project was completed in Spring of 2011.

Grain and Flour

Grain shipments from Duluth and Superior began to rise quickly in the late 1870s, reflecting the rapid expansion of Midwestern agriculture. By the late 1880s, the harbor had emerged as a vital gateway for moving grain from farms to national and international markets. A major turning point came in 1884 with the completion of the Sault Canal at Lake Superior’s outlet, which allowed larger ships to reach the Duluth–Superior harbor. With direct access to waterfront grain terminals, ships could unload and reload efficiently, dramatically reducing turnaround times compared to busier ports like Chicago.

By 1886, Duluth–Superior had become the largest wheat shipping port on the Great Lakes—a distinction that underscored its growing importance. This momentum continued well into the 20th century. Between 1919 and 1935, nearly 20 percent of all grain shipped on the Great Lakes passed through the Duluth–Superior harbor. The scale and consistency of this activity firmly established the port as a cornerstone of the Great Lakes grain trade.

The physical landscape of the harbor reflected this growth. As early as 1885, 11 grain elevators lined Rice’s Point in what would soon be known as “Elevator Row.” By 1918, that number had grown to 25 towering structures along the waterfront. Rail connections further strengthened the port’s role. During the 1880s, Superior welcomed its first railroad line, and by 1886, J.J. Hill’s Great Northern Railroad had constructed the first grain elevator on the Wisconsin side of the harbor.

Superior’s reputation for hosting some of the largest grain elevators in the region took shape in the mid-20th century. The construction of the Farmers Union Grain Elevator in 1941 at the entrance to Howard’s Bay (Howard’s Pocket) marked a new era of scale and capacity. This legacy was reinforced in 1965 with the completion of the Continental Grain Elevator on Connor’s Point in Superior Bay, further cementing the harbor’s identity as a powerhouse of grain movement on the Great Lakes.

Petroleum

Standard Oil Company built the first dock for the receipt of petroleum products on the Superior side of St. Louis Bay in 1891. Although petroleum receipts have been less important to the Duluth-Superior economy than the iron and coal industries, an abrupt increase in shipments was seen in 1910, likely due to the established presence of the automobile industry in the Twin Ports. Like the coal and iron ore industries, petroleum increased with the advent of World War I and II. The years between 1932 and 1946 were busy years for this industry. After World War II, petroleum receipts abruptly declined and continued to decline into the 1960s. Lakehead Pipeline Company constructed the largest and most modern petroleum shipping terminal in the harbor in 1951, replacing the old Northern Pacific Coal Dock on the Superior Bay channel. Its shipment of petroleum products to Canada was impressive, but short lived. By the end of the decade, a Canadian pipeline was completed and most shipments ceased.

Shipbuilding

Shipbuilding in the Duluth–Superior harbor experienced a major boom as barges replaced sailing vessels and the industry transitioned from small wooden ships to large steel freighters. The N. Grignon Shipyard, the largest builder of wooden vessels on the harbor, operated from 1880 to 1895. A pivotal moment came in 1889, when Captain Alexander McDougall founded the American Steel Barge Company and built the first steel vessels in the Duluth–Superior harbor.

Between 1888 and 1892, McDougall constructed more than thirty distinctive “whaleback” vessels for use on the Great Lakes. The first five whalebacks were built in Duluth, while the remaining steamers were completed in Superior. These unique ships were based on McDougall’s own innovative designs. He later sold his interests to an eastern investment group, which continued operating the yard under the name American Shipbuilding Company.

The two World Wars had a profound impact on shipbuilding in Duluth–Superior. During World War I, McDougall established a second yard—the McDougall Duluth Shipbuilding Company—in the Riverside section of Duluth. Although the yard operated only briefly and closed in 1922, it constructed 25 coastal freighters for the federal government. During this same period, the Whitney Brothers Shipbuilding wharf built ten steel tugs in 1919 for the U.S. Shipping Board, and Globe Shipyard constructed 19 ocean freighters, each measuring 260 feet in length, under a government contract.

Shipbuilding activity surged again during World War II. The Globe Shipbuilding Company, Marine Iron Shipbuilding Company, and Barnes Duluth Shipbuilding Company (later known as Walter Butler Shipbuilders, Inc.) were reactivated and expanded to meet wartime demand. In total, approximately 230 ships were built by eight different shipyards across the Duluth–Superior harbor during the war. These facilities closed following the war, and by 1970, Fraser Shipyards, Inc. remained the only major shipyard operating in the Duluth–Superior harbor.

Shipping

During the latter part of the nineteenth century, the ports of Duluth and Superior were established as major components of the nation’s rapidly expanding shipping industry. Vigorous development efforts, combined with the area’s naturally advantageous land and water features, enabled Duluth and Superior to build and maintain a strong presence in the transshipment industry.

Today, the Duluth–Superior harbor contains 15 major cargo terminals, including six multi-purpose bulk terminals, one general cargo distribution center, two ore docks, one coal dock, and seven grain elevators with a combined storage capacity of 55 million bushels. The port’s principal cargoes consist of approximately 40 percent iron ore, 40 percent coal, and 10 percent grain.

Currently, the Duluth–Superior Harbor is ranked as the number one port on the Great Lakes by cargo tonnage and among the top 20 ports nationally, handling about 33–35 million short tons of cargo and hundreds of vessel visits annually, and generating more than $1 billion in economic activity each year.

St. Louis River Area of Concern

In 1989, the St. Louis River was designated an Area of Concern (AOC) under the U.S.–Canada Great Lakes Water Quality Agreement, identifying it as one of the 43 most polluted sites in the Great Lakes. This designation stemmed largely from historical industrial practices, including the dumping of waste on land and directly into the water—activities that were common prior to modern environmental regulations. These practices left behind legacy pollutants that have contributed to nine major impairments affecting beneficial uses such as fishing and recreation. Extensive wetland filling and dredging throughout the river have also resulted in significant loss of fish and wildlife habitat.

Since the AOC designation, Minnesota and Wisconsin state agencies have worked collaboratively with federal and tribal partners, as well as numerous non-governmental organizations, to develop and implement a comprehensive plan to address these nine areas of concern. As of 2013, these coordinated efforts had resulted in the cleanup of contaminated sediments and the protection and restoration of fish and wildlife habitat. A multiyear strategic plan was established with the goal of removing the St. Louis River from the Area of Concern list by 2025. And though the original 2025 delisting goal was met, much progress has been made. Learn more here.

Superfund Sites

Citizen concern about seriously polluted sites led Congress to establish the Superfund Program in 1980 to locate, investigate, and clean up the nation’s most contaminated hazardous waste sites. The Environmental Protection Agency administers the Superfund Program in cooperation with state and tribal governments.

In the St. Louis River area, two large Superfund sites remain the focus of long-term cleanup and restoration efforts: the St. Louis River/Interlake/Duluth Tar (SLRIDT) site and the U.S. Steel site, which together make up the 755-acre St. Louis River Superfund site near Duluth, Minnesota. Industrial operations dating back to the late 1800s contaminated soils, sediments, groundwater, and river habitat with tar, polycyclic aromatic hydrocarbons (PAHs), heavy metals, and other pollutants, prompting the sites’ addition to the National Priorities List in the early 1980s.

At the SLRIDT site, significant cleanup work—including tar and soil removal, dredging and capping of contaminated sediments, and wetland habitat reconstruction—has been completed, and parts of the site now support light industrial reuse.

At the U.S. Steel site, cleanup has recently advanced through the Great Lakes Legacy Act partnership, focusing on sediment remediation and habitat restoration in areas including Spirit Lake. In July 2024, EPA and its partners announced the completion of a multi-year sediment cleanup and restoration project at Spirit Lake, which removed contaminated material, capped sediments, and created new recreational access, waterfront trails, and improved fish habitat.

While these major accomplishments mark important progress, work at both sites continues, with remaining cleanup tasks, habitat restoration, and beneficial use improvements still underway as part of broader efforts to restore environmental and cultural resources in the St. Louis River area.