Indiana limestone — also known as Bedford limestone — is a common regional term for Salem limestone, a geological formation primarily quarried in south central Indiana, USA, between the cities of Bloomington and Bedford.
Bedford, Indiana, has been noted to have the highest quality quarried limestone in the United States. Salem limestone, like all limestone, is a rock primarily formed of calcium carbonate. The limestone was deposited over millions of years as marine fossils decomposed at the bottom of a shallow inland sea which covered most of the present-day Midwestern United States during the Mississippian Period.
Native Americans were the first people to discover limestone in Indiana. Not long after they arrived, American settlers used this rock around their windows and doors and for memorials around the towns. The first quarry was started in 1827, and by 1929 Hoosier quarries yielded 12,000,000 ft3 (340,000 cubic meters) of usable stone. The expansion of the railroads brought great need for limestone to build bridges and tunnels and Indiana was the place to get it.
American architecture of the late 19th and early 20th century included a lot of limestone detail work on buildings, but as architectural styles changed, so did the demand for limestone. Salem limestone was officially designated as the state stone of Indiana by the Indiana General Assembly in 1971.  With the Arab Oil Embargo of 1973, the price of alternative building materials skyrocketed so Indiana limestone reemerged as an energy-efficient building material. 
Indiana limestone is part of a high-end market. It is mostly used on the exterior of homes and commercial buildings. With the impact of acid rain it is not used in monuments as it was in the 19th century. Many of Indiana's official buildings, such as the State capitol building, the monuments in Downtown Indianapolis, the Benjamin Harrison School of Law in Indianapolis, many university buildings across the United States, and the Indiana Government Center, and most of the state's 92 courthouses are all examples of Indiana architecture made with Indiana limestone. Indiana limestone has also been used in many other famous structures in the United States, such as the Empire State Building, the Pentagon, Yankee Stadium, and the Washington National Cathedral. In addition, 35 of the 50 state capitol buildings are made of Indiana limestone. 
Buildings such as the National Cathedral, Biltmore Estate, Empire State Building, the Pentagon, The Crescent in Dallas, and the Hotel Pennsylvania feature Indiana limestone in their exteriors. Indiana limestone was used extensively in rebuilding Chicago after the Great Chicago Fire. 1959's architecturally significant St. Augustine's Episcopal Church uses Indiana limestone in the interior. The Saint Sava Serbian Orthodox Church in Merrillville, Indiana, consecrated in 1991 and awarded a Gold Medal Award for Excellence in Masonry Design, uses Indiana limestone on its exterior facade. The new Yankee Stadium in the Bronx, which opened in 2009, extensively uses Indiana limestone paneling on its exterior facade. The original 1930s buildings of Rockefeller Center use limestone from Bedford. In 1955 the Tennessee State Capitol exterior was renovated using Indiana limestone to replace the poorer quality Tennessee limestone that had started to deteriorate. Indiana limestone was used in the rebuilding of the Pentagon after the terrorist attack of Sept. 11, 2001. The project took around 15,000 cubic feet of stone and was rededicated exactly one year after the attack. 
Indiana limestone has been particularly popular for the construction of university buildings. The Neo-Gothic campus of the University of Chicago is almost entirely constructed out of Bedford limestone; in keeping with the trend of post-Fire buildings using the material. The campus of Washington University in St. Louis – both for new construction and original buildings – makes use of Indiana limestone (along with Missouri Red Granite) in its collegiate gothic architecture. The majority of Indiana University, Bloomington, was constructed out of limestone. In addition, many buildings on the north side of Michigan State University use Indiana limestone. The Cathedral of Learning, a 42-story neo-gothic skyscraper that is the largest educational building in the Western Hemisphere, along with other nearby buildings of the University of Pittsburgh, are clad in Indiana limestone. The St. Anthony Society Chapter House at Yale University also is built of Indiana limestone.  Both structures of the Kenosha County Courthouse and Jail in Kenosha, Wisconsin, were built out of the limestone. The rock was used as far north as the Hotel Macdonald in Edmonton. Several buildings on the campus of Washington University in St. Louis incorporate Indiana limestone and many of the academic buildings are listed on the National Register of Historic Places. 
- "Indiana State River and Indiana State Stone".
- "History of Indiana Limestone". Retrieved 2007-07-11.
- "Lawrence County Limestone History". Lawrence County, Indiana. Archived from the original on 2006-10-30. Retrieved 2007-09-11.
- "Pentagon". Bybee Stone Company. Retrieved 19 January 2017.
- "VANDERBILT GIFT TO 'SHEFF'; Frederick W. to Build..." (PDF). The New York Times. 1913-07-09.
- "Washington University". Bybee Stone Company. Retrieved 19 January 2017.
- Patton, J.B. and Carr, D.D. (1982), "The Salem Limestone in the Indiana Building-Stone District"; Ind. Dept. of Nat. Res. Geol Surv. Occasional Paper 38, 31 p.
|Wikimedia Commons has media related to Quarries in Indiana.|
- Indiana Bedrock
- Indiana Geological Survey explanation of Indiana limestone
- Indiana limestone Institute of America
- Indiana Limestone: The Aristocrat of Building Materials, June 1920, Vol. 1, 6th Edition, Indiana Limestone Quarrymen's Association, Bedford, Indiana.
- Indiana stone quarry information on Stone Quarries and Beyond