Jefferson Proving Ground

The Jefferson Proving Ground (JPG) was a U.S. Army munitions testing facility located in southeastern Indiana.

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History
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The Jefferson Proving Ground (JPG) was a U.S. Army munitions testing facility located in southeastern Indiana. For much of the 20th century, it played a key role in the nation’s military-industrial complex by supporting the testing and development of various types of ordnance, as well as the storage and issuance of ammunition and calibrated ammunition components. Its firing ranges could accommodate weapons ranging from small arms and grenade launchers to 240-mm howitzers.

History

Establishment

On October 8, 1940, the Chief of Ordnance of the United States Army identified the need for a proving ground to support ordnance testing as part of the expanding munitions manufacturing program. This decision was driven by growing global tensions and the anticipated entry of the United States into World War II. A site spanning Jefferson, Ripley, and Jennings counties in Indiana was selected due to its relative isolation, access to rail transportation, and proximity to existing military facilities. These included the Indiana Arsenal in LaPorte County, an ammunition storage depot in Martin County, and military installations at Fort Benjamin Harrison in Indianapolis, Fort Hayes in Ohio, and Forts Thomas and Knox in Kentucky.

In December 1940, the federal government acquired over 55,000 acres of farmland and woodland for the Jefferson Proving Ground. ⁷ This acquisition displaced between 500 and 600 families and led to the abandonment of several small communities, including Marble Corner and Zenas. Residents were given between 30 and 120 days to vacate their properties. The Paul L. McCord real estate firm of Indianapolis served as the government’s agent in managing the land acquisition. Homes, farms, cemeteries, and churches were either demolished or repurposed for military use.

Construction

Thirteen farmhouses, originally built between the 1880s and 1930s, were relocated to the southern section of the Jefferson Proving Ground for use as family housing. ⁷ These homes were arranged along a U-shaped road and renovated with new concrete block foundations. Their original siding was replaced with aluminum or asbestos-cement materials.

In December 1940, the War Department awarded a design services contract to the Indianapolis architectural firm of William Earl Russ and Merritt Harrison for the development of facilities on the southern portion of the proving ground. ⁷ A joint construction contract was also signed with the J. L. Simmons Company of Indianapolis and the J. C. O’Connor Company of Fort Wayne for general construction work. Construction began on January 1, 1941, starting with 14 miles of rail lines and roads. Due to the urgent need for ordnance testing, priority was given to completing the firing facilities, which included reinforced concrete safe houses and 268 firing points along the firing line. By June 1941, the firing line was completed. Simultaneously, reinforced concrete observation structures, covered with earth for protection, were constructed uprange. Testing officially began on May 12, 1941, even before all firing facilities were finished.

Additional buildings were constructed south of the firing line during this period. ⁷ Most of these were testing, maintenance, storage, and assembly facilities built from brick and reinforced concrete. A small number of semi-permanent wood-frame administration and support buildings were also erected during the war. By the end of World War II, 149 structures had been completed at the site, with more than two-thirds built during the initial construction phase in 1941.

One of the proving ground’s original missions was to test aerial bombs. ⁷ In 1941, a hangar was built on the southwest side of the installation to accommodate bombers and pursuit planes. Three 5,000-foot runways were constructed nearby. Six ammunition storage igloos were also built during the initial construction period, with three additional igloos added in 1943.

The largest administrative facility was the Post Headquarters, a two-story structure built in 1941 and expanded with a southern wing in 1953. ⁷

After the end of the war, ammunition testing and production declined sharply. On September 10, 1945, Jefferson Proving Ground was deactivated, and its 149 buildings were mothballed. ⁷ Wartime employment dropped from nearly 1,300 workers to just 51 maintenance and security staff. Several thousand acres were subleased to local farmers for grazing and cultivation.

In April 1946, the proving ground became a subinstallation of the Indiana Arsenal. ⁷

A second major construction phase occurred between 1951 and 1953 during the Korean War, resulting in the addition of 107 new buildings, primarily for ammunition testing and storage. ⁷ Only a few buildings were constructed in the 1970s during the Cold War.

By the time it closed, the Jefferson Proving Ground was divided into two sections: a 20,640-acre firing range in the north and a 4,000-acre cantonment area in the south. ⁸ The cantonment area contained buildings for maintenance, utilities, administration, ammunition assembly, test ranges, training, and housing. The two areas were separated by the firing line.

Operations

During World War II and the Korean War, the Jefferson Proving Ground played a vital role in testing munitions in support of the war effort. ⁷ The facility’s infrastructure included firing ranges, laboratories, storage areas, and various support buildings. The onset of the Korean War led to its reactivation in 1949 for the testing of ammunition ranging from 20 mm to 240 mm, along with mines, hand grenades, and component parts. ⁷ By April 1953, the installation had reached its peak level of activity, employing 1,774 military and civilian personnel and firing approximately 175,000 rounds per month. ³

Ammunition production declined steadily after the Korean War, leading to reduced testing activity. ⁷ On October 1, 1958, the installation was placed on standby.

The Jefferson Proving Ground was reactivated again in 1961 as the U.S. military entered the Cold War. ⁷ Testing operations continued through the Korean and Vietnam wars and into the 1980s, with the facility adapting to emerging technologies and evolving weapons systems. It became particularly noted for its long-range artillery testing, including the use of a 20-mile-long firing range for live munitions.

Since 1977, approximately 1,000 acres of the proving ground have been used by the Indiana Air National Guard for air-to-ground impact training. ^{3 8}

Between 1984 and 1994, the U.S. Army conducted tests of armor-piercing depleted uranium rounds at the site to assess their accuracy. ³

Closure and Reuse

In 1989, as part of the post–Cold War Base Realignment and Closure (BRAC) process, the Department of Defense designated the Jefferson Proving Ground for closure. ⁹ Operations were to be transferred to facilities not yet built at Yuma, Arizona. Active military operations began to wind down in 1991 and ended on September 30, 1995. Operations were relocated to the U.S. Army Yuma Proving Ground, with the Nuclear Regulatory Commission license transferred to the U.S. Army Test and Evaluation Command (TECOM) at the Aberdeen Proving Ground in Maryland in 1996. ⁸ By that time, decades of weapons testing had resulted in significant contamination from unexploded ordnance and hazardous materials, rendering large areas unsuitable for civilian use. Over 24 million rounds of conventional explosive ammuition were fired between 1941 and 1994, including 220,462 pounds of tank penetrator rounds containing depleted uranium between 1984 and 1994.

Following its closure, the property was divided for multiple uses. The U.S. Army retained a small on-site oversight staff and designated an off-site environmental coordinator. The installation has since been managed by the BRAC Division within the Army’s Installation Management Agency.

In 1997, a Memorandum of Agreement between the U.S. Army Test and Evaluation Command (TECOM) and the U.S. Fish and Wildlife Service established a plan to manage the northern firing range based on ecosystem principles. ^{3 8} In 1998, a Memorandum of Understanding was signed by the U.S. Army, the Air National Guard, and the Indiana Air National Guard. It allowed the Air National Guard to continue using the 1,033-acre bombing range in exchange for maintaining and operating the northern firing range. ^{3 5 8} This agreement was superseded in May 2000 by a new Memorandum of Agreement involving the U.S. Army, the U.S. Air Force, and the U.S. Fish and Wildlife Service. ^{3 8} The updated agreement authorized continued use of the firing range by the U.S. Air Force for 25 years, with options for 10-year extensions, and allowed future use by the Fish and Wildlife Service.

In June 2000, approximately 50,000 acres north of the historic firing line were leased to the U.S. Fish and Wildlife Service, which established the Big Oaks National Wildlife Refuge. ^{6 8} Due to the presence of unexploded ordnance, public access to the refuge remains limited and strictly controlled.

As of 2025, the Air National Guard uses its bombing range for unmanned aerial vehicle (UAV) training, including air-to-ground strike exercises. ⁶ Portions of the site’s railroad infrastructure are currently used by the Madison Railroad for railcar storage.

Environmental Concerns

In December 2014, the Nuclear Regulatory Commission (NRC) held a public meeting in Madison, Indiana, to gather input on the U.S. Army’s request to relinquish responsibility for monitoring depleted uranium at the former Jefferson Proving Ground. ³ Richard Hill, representing the environmental group Save the Valley, advocated for continued monitoring should the Army’s request be approved.

Three alternatives were presented: ³

No Action: The existing license would remain in effect, and the Army would continue its monitoring responsibilities.
Proposed Action: The NRC would terminate the license, contingent upon the Army retaining ownership of the property.
Other Alternatives: Additional options to be developed through the ongoing study process.

The Army stated that, if the license were terminated, it would maintain control of the site through the following measures:

Physical controls, including perimeter fencing and security signage;
Legal controls, with the Army retaining property ownership;
Administrative controls, such as restricting public access and regulating activities like hunting.

The Army maintained that the presence of depleted uranium and a high density of unexploded ordnance made environmental cleanup both hazardous and cost-prohibitive. ³ An estimated 162,000 pounds of depleted uranium remain in the testing area, along with approximately 1.5 million rounds of unexploded ordnance.

Gallery

Sources

United States, Department of the Army. Realignment and Closure Progress Report.
Brown, Rachel Christing (Fulk). “Sacrificing for the ‘Arsenal of Democracy.’” The Hoosier Genealogist: Connections, vol. 57, no. 2, Fall 2017, pp. 34–39. Indiana Historical Society.
Tompkin, Elliot. “Army wants to halt uranium testing at JPG.” Madison Courier, 4 Dec. 2014.
“National Register Information System.” National Register of Historic Places, National Park Service.
“Facilities.” Indiana National Guard, 2010.
“Railcar Storage.” Madison Railroad.
Hightower, Barbara E. and William A. Brenner. “Jefferson Proving Ground, Madison, Jefferson County, IN.” Historic American Engineering Record, 1984.
“Jefferson Proving Ground.” United States Nuclear Regulatory Commission.
Latham Charles. “JEFFERSON PROVING GROUND RECORDS, 1951-1993.” Indiana Historical Society, 19 May 2004.