2-27-2026 10:26pm

Carillon Park's Mound Cold War Discovery Center Opens

Beth Callahan Editor

Story and photo courtesy of Dayton History

DAYTON, OH -- Carillon Park’s Mound Cold War Discovery Center was dedicated before more than 200 guests during a members-only ceremony on Feb. 26, 2026, at 5 p.m.

Created by Dayton History in partnership with the U.S. Department of Energy, Mound Development Corp., and Mound Science and Energy Museum Association, the exhibit is now permanently installed at Carillon Park. It preserves artifacts, images, and stories from Mound Laboratory, the nation's first post-World War II Atomic Energy Commission site.

Highlighting the thousands of employees whose work helped change the world, the Discovery Center invites visitors to explore how Mound Laboratory shaped the Cold War, the Nuclear Age, and the Space Race. The exhibit is presented by River Valley Credit Union, and is now open to the public.

"The Mound operated only eight miles southwest of Carillon Park," says Brady Kress, President & CEO of Dayton History. "Our community has long been a powerhouse of research, innovation, and manufacturing. Over 75 years ago, Col. Edward A. Deeds founded Carillon Park to share the region's stories of ingenuity with the world. The Mound story fits perfectly into that mission."

Operating from 1948 to 2003 in Miamisburg, Ohio, Mound Laboratory — named for the neighboring Adena earthwork, one of North America's largest conical mounds — carried out work so top-secret that some projects remain classified today. The facility grew out of the wartime Dayton Project, part of the Manhattan Project, which transformed obscure sites — a seminary, a warehouse, an opulent playhouse — into laboratories, ultimately producing the polonium-based trigger used in the Trinity test "gadget" and Fat Man atomic bomb.

"At its peak, the Mound employed approximately 2,500 scientists, engineers, and skilled workers across 116 buildings, all working collectively on some of the biggest projects of the past century," says Lee Spivey, CEO of River Valley Credit Union, presenting sponsor of the Discovery Center. "It was with that same collective spirit that a group of Mound employees got together in 1949 to found the Mound Employees Federal Credit Union, now River Valley Credit Union."

Several former Mound employees attended the dedication ceremony at Carillon Park, Dayton History's 65-acre open-air history museum, where the story of their life's work will now be shared with approximately 250,000 guests each year.

"The Mound story stands as another chapter in Ohio's world-changing history, now told alongside stories of the Wright brothers, Delco, Henny Penny, and more," says Kress. "We couldn't be more grateful to the former Mound scientists and engineers who helped us tell these stories, ensuring the accuracy of their amazing accomplishments at Mound Laboratory.”

Located in the Ken and Nancy Quinter Gallery, a highlight of the exhibit is a talking animatronic figure of Charles A. Thomas, head of the Dayton Project and deputy to Robert Oppenheimer. Thomas, who was awarded the Medal of Merit by President Harry S. Truman, was also the President and Chairman of Monsanto Chemical Company, the firm that operated Mound Laboratory.

"Although the Mound site is no longer active," says Spivey, "its legacy and achievements are now preserved at the Mound Cold War Discovery Center. We hope it will help the thousands of visitors to Carillon Historical Park appreciate the significant contributions the Mound made to our community and to our nation."

About Dayton History:

Dayton History, a privately funded nonprofit organization, owns and operates Carillon Historical Park, Hawthorn Hill, and Patterson Homestead. Serving as Montgomery County’s official historical organization, its mission is to inspire generations by connecting them with the unique people, places, and events that changed Dayton and the world. For more information, visit daytonhistory.org.

About River Valley Credit Union:

River Valley Credit Union has been serving the Greater Miami Valley region for 77 years with state-of-the-art banking and loan services. As a community-chartered credit union, membership is open to anyone in Southwest Ohio who lives, works or attends school in one of these counties: Montgomery, Greene, Butler, Warren, Preble, Clark or Miami.