California Institution for Men

The California Institution for Men is a state correctional facility in Chino, California, covering more than 1,000 hectares (about 2,500 acres) of flat terrain. The complex holds several separate units with different security levels, surrounded by open, dry land.

The facility opened in 1941 as California's fourth state prison and was the first major minimum-security institution in the United States. The original design omitted walls and used open dormitories to encourage reintegration.

The prison incorporated rehabilitation programs including commercial diving training, which reduced recidivism rates among participating inmates to 12 percent.

The institution lies in Chino, about 65 kilometers (40 miles) east of Los Angeles, in an area with sparse vegetation and open sky. Access is tightly controlled, and visitors must register in advance and pass through security checks.

In the 1960s, the institution introduced a commercial diving program that trained inmates in underwater techniques. Graduates of this program later showed a recidivism rate of only about 12 percent.

Location: California

Inception: June 21, 1941

Official opening: June 21, 1941

GPS coordinates: 33.98200,-117.68200

Latest update: December 14, 2025 19:47