International Salt Co.

500 Million years ago, the area surrounding the Great Lakes was an ancient salt water body. 100 million years following that time, the sea dried up due to volcanic activity, creating the Silurian, or salt formation. Movement of glaciers in the region covered the 100 foot thick layer of salt. This highly useful material that we define as rock salt was discovered in the latter half of the 1950s by a test drilling company hired by International Salt Co.

At that time, it was determined by International Salt that production could reach 1.5 million tons of the material per year, and the deposit itself could hold 170 million tons, and they were granted a lease by the State of Ohio to mine the material under the lake. A peninsula known as Whiskey Island in Cleveland, Ohio was set as the location for operation, and construction of the mine began in 1958.

Upon the completion of construction in 1961, the depth of the mine reached 1,800 feet, or two-and-a-half times the height of the Terminal Tower. An elevator shuttled men and machinery down the mine’s shaft to corridor dubbed “main street,” or the main drag of the mine. International Salt used the ‘room and pillar’ method to extract the salt. 50% of the salt is left behind in the form of columns 100 feet in diameter to support the ground and Lake Erie above. This is done by drilling into the salt and pumping it full of an explosive, called ammonium nitrate. Rooms measuring 30’ by 40’ and 16’ high are left behind, along with roads connecting the rooms measuring 40’ feet wide.

Due to the physical characteristics of the mine, and the fact that it stretches over two miles out from the shoreline, people have called it an “underground city.” International Salt’s underground city has been a major industry for the city of Cleveland, which offered over 200 jobs to run the mine. The union-based job offered year-long employment because the mine was kept at a constant temperature of 75 degrees.

Mining was interrupted in 1981 when the United States Department of Energy requested use of the mine for an experiment involving nuclear waste. The DOE proposed experiment would determine if the mine could safely house nuclear waste. Even though the DOE promised that the mine would not become an N-waste dump, Clevelanders and officials were outraged, and protests followed. The DOE refused to drop plans of the tests, despite bitter objections from leading protester, Representative Mary Rose Oakar, who claimed that the DOE was lying about the true intentions of the tests. Finally, in February 1982, Cleveland City Council passed an ordinance to restrict the testing, which resulted in the surrender of the DOE to press forward.

The mine is still in operation today, owned and operated by one of the world’s largest producers of rock salt, Cargill Incorporated. The mine does not offer tours, leaving media as the only means for the public to experience it.








"Main Street"

"Main Street"

Photograph Courtesy of Cleveland State University, Michael Schwartz Library, Special Collections, Cleveland Press Collection, James Thomas, 7/13/1962

This photograph, taken in 1962 is a picture of what International Salt Co. workers deemed “Main Street.” It was given the name due to its utility as the main corridor for entering and exiting the mine. At 1,800 feet below the surface this particular street was 40 feet wide and 30 feet high, making it an ideal location to  reassemble heavy machinery that was sent down the elevator shaft to extract rock salt under Lake Erie.


Room and Pillar

Room and Pillar

 Photo courtesy of

The room and pillar photograph shows the hollowed Salina salt formation after salt extraction. The method of mining used is called “room and pillar,” where explosives are used to blast rooms roughly 40 feet in diameter, and 16 feet high, while 100 foot sections are left to support the ground above. The salt is loaded onto an elevator where it is transported to the surface. A vast network of rooms like this extend about three miles out under Lake Erie.

Aerial View

Aerial View

Photo courtesy of Cleveland State University, Michael Schwartz Library, Special Collections, Cleveland Press Collection, James Thomas, 3/18/1960

This arial photgraph taken in 1960 shows the size of the mine’s facility. Notice the large barges towards the top of the picture. The facility was able to transport rock salt to the Cuyahoga River which empties into Lake Erie. The facility was also in proximity to railroads making the site of the mine an excellent location to transport its product.

Photo courtesy of Cleveland Public Library, Cleveland Plain Dealer, 12/7/1958

This advertisement was published to attract business owners to buy International Salt’s deicing salt. In this context, a slip hazard was threatening to business owners for various reasons. The cartoon depicts total chaos at Sam’s storefront. This advertisement was published before the mine was in production.



5 thoughts on “International Salt Co.

  1. Profile photo of keylahjallenkeylahjallen

    This post was very informative, but the absences of employees remind me of the post cards we studied in class which give the illusion of the reality of the mines. Thank you for the information that was provided because, I learned alot.

  2. Profile photo of davebraunlichdavebraunlich

    I liked the geographic information in the first paragraph! I didn’t know that there was any sort of volcanic activity in the region, so that’s interesting to learn.

    Though this could just be something that struck me and only me, but there were a few things that struck me reading this that lead me to ask questions. What is the “Room and Pillar” method? I could take some guesses from the pictures, but I can’t really say. Along those lines, if the mine is under Lake Erie, what sort of problems do they have? Does the mine need to be supported underneath the weight of the lake? Are there leaks, and the need for pumping water like other types of mines?

    The only big thing that I noticed as a bit of an issue was the large space between the introductory narrative and the pictures. Overall this was well written and free of grammatical and spelling errors. Good job!

  3. Profile photo of Nick OrehNick Oreh

    Very well written post.
    A little more information about the International Salt Co. would add to the story a little.
    Also, more info on the impact of the salt mine on the economy of Cleveland then and today might help add to the story of Cleveland as a whole.
    Why does the mine not offer tours? Is it too dangerous?
    If there are pictures of workers in the mine, they might add a little depth to understanding the work done under the lake.

  4. Profile photo of ronniebrehm9ronniebrehm9 Post author

    Thanks for the advice! I realized what i did wrong. I tried to do three photos to one post. There was a separate box that had caption, title, and description that I typed the text in, but it didn’t show up when I posted it. Thanks for the help!

  5. Profile photo of Mark TebeauMark Tebeau

    This is a great start.
    You need to identify the photo, underneath it with the appropriate credit line, as you did on your Omeka poster.
    You should do this for each image.
    Also, be sure to “tag” this post with clear identifiers, such as salt, industry, downtown, cuyahoga.
    And, finally, be sure to identify where it should be located on a map and start thinking about your text.

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