Helen Jernigan arrived in Oak Ridge after finishing her first year in college at Tennessee Wesleyan College. Jernigan was a member of a folk dancing group that participated in the opening of the Happy Valley Theater. Happy Valley, a construction camp located near the K-25 gaseous diffusion plant, was established to lessen the traveling time for the 17,000 construction men working there.
The following summer, Jernigan returned to Oak Ridge and was offered a job working in the recreational facilities. There, she helped manage events and encouraged other Oak Ridgers to participate in activities such as horseback riding and golf. Eventually, she moved on to become associate editor of the K-25 plant newspaper, the Carbide Courier.
After the war, Jernigan remained in Oak Ridge and worked for several local newspapers in the area. Later, Jernigan was elected as the court clerk for Anderson County, where she served three terms.