The War Department approved construction on March 25, 1943, and the facility was receiving patients less than a year later. The site chosen was agricultural land in the Sierra foothills - fruit orchards and farms that were quickly cleared for eighty one-story buildings of brick and stucco. The hospital was named for Brigadier General Calvin DeWitt, a Civil War-era surgeon who had served in the Medical Corps from 1840 to 1908. Briefly called Auburn General Hospital at its opening, it was renamed almost immediately. Beyond the wards, the campus included a chapel, a rehabilitation pool, a gymnasium, a fire station, a movie theater, a kitchen, and its own power plant. DeWitt was not just a hospital - it was a self-contained community, designed to function independently of the small town it dwarfed. The facility served soldiers returning from the Pacific and European theaters, but also drew patients from nearby installations: Camp Beale, Camp Kohler, McClellan Field, Sierra Army Depot, Reno Army Air Base, and Chico Army Air Field.

Adjacent to the hospital, a place called Camp Flint took on its own wartime role. The camp had been built in 1938 as a Great Depression labor camp - a public works project where unemployed men lived in wood and canvas huts while working on federal and state construction. When Pearl Harbor was attacked, the Army repurposed it immediately. Soldiers of the 32nd Infantry Division arrived on December 9, 1941, establishing Camp Flint as a base for guarding the Southern Pacific Railroad's tunnels and bridges through the Sierra Nevada against sabotage. In February 1942, the 754th Military Police Battalion took over those security duties. Then, in June 1945, two hundred German prisoners of war were transferred from Florence, Arizona, to Camp Flint to provide labor supporting DeWitt General Hospital. At its peak, the camp held over five hundred POWs, secured by additional fencing and guard towers. The prisoners remained at Camp Flint through February 1946, two months after the hospital itself had closed.

The Army closed DeWitt General Hospital on December 31, 1945. Efforts to convert it into a Veterans Administration hospital were rejected. Instead, on March 31, 1946, the War Assets Administration sold the facility to the State of California with conditions: it was to be used as a mental institution, could not be resold for twenty-five years without Army approval, and had to submit to reporting requirements. The state complied. By 1947, patients were transferring in from other state hospitals, and by July 1950 DeWitt State Hospital was admitting patients directly from surrounding counties - Placer, Modoc, Lassen, Sierra, Yuba, Sutter, and El Dorado. The facility that had been built for wounded soldiers now housed people struggling with mental illness, and the population grew to 2,800 patients at its peak in 1960. The conditions and treatments of mid-century state mental hospitals are well documented and often grim. DeWitt State Hospital operated for exactly its required twenty-five years, closing in 1972.

On April 1, 1972, the property transferred to Placer County. The eighty brick buildings that had housed soldiers, then prisoners, then psychiatric patients began their latest incarnation as government offices. Today the site contains the Placer County Jail, the Juvenile Detention Facility, Adult System of Care services, Human Services, Vital Statistics, and Community Health offices. Parts of the complex serve commercial tenants, a church, and a farmers' market. About thirty percent of the original buildings have been demolished, but the remainder still stand - low-slung brick structures that look exactly like what they are: military construction from the 1940s, built for function rather than beauty, proving surprisingly durable across uses their builders never imagined. A historical marker and the Gold Country Museum preserve the memory of Camp Flint on the adjacent fairgrounds. The hospital's story is one of continuous reinvention, each chapter reflecting what the country needed from this particular patch of foothill land at that particular moment in history.