In the Sand Hills region of South Carolina, near the Georgia border and along the serpentine Savannah River, sits a sprawling nuclear reserve with roots that took hold during the Cold War.

On maps, the area is often represented as an untouched blot, a rough circle with little detail and a single label: Savannah River Site.

Established in the early 1950s, the site (then known as the Savannah River Plant) was cloaked in Cold War confidentiality and was built amid the resultant international nuclear frenzy. For SRS to be constructed, land in several counties was eventually acquired by the government and families had to be relocated.

The site was designed for production. It pumped out a significant share of the country's weapons-grade plutonium as well as a wealth of tritium. Both materials, the latter a radioactive hydrogen isotope, are crucial nuclear weapon components. That work garnered the site the lingering nickname of "The Bomb Plant."

But materials produced at the site were sent to other federal installations where weapons were actually manufactured. The first batch of plutonium was shipped out in 1955, according to a timeline provided by the U.S. Department of Energy, the site's contemporary owner.

The site also provided nearly all the plutonium-238 for the deep-space exploration missions that needed it. That plutonium was used as a nuclear battery, of sorts. The American Chemical Society formally recognized SRS for those contributions last year.

As the Cold War cooled, though, the site pivoted and transitioned to what it is now. No longer is the site a wartime hub. And gone are the days of its behemoth outputs. Simply put, the Savannah River Site of today is vastly different than the site of yore.

These days, it's home to a major, decades-long cleanup effort — a tidying of the local Cold War legacy.

The Savannah River Site employs thousands. It's Aiken County's single largest economic driver. Every day, workers flow to and from the site, filling roads throughout the two-state region. 

Nuclear- and other energy-related work is ingrained in the culture and atmosphere in Aiken, a city of about 30,000 known for its historic charm, equestrian heritage and its Winter Colony underpinnings. The city is about 15 miles north of SRS and has a direct feed to the site by way of Whiskey Road, a corridor in some parts lined by fast-food joints, and in others horse paddocks and starter homes.

Colin Demarest covers the Savannah River Site, the U.S. Department of Energy, the National Nuclear Security Administration and government in general. Follow him on Twitter: @demarest_colin