The move was first reported by the L.A. Daily News.
The Los Padrinos Juvenile Hall hasn't housed youth prisoners since 2019.
It comes ahead of the state's order for L.A. County to shut down two of its juvenile hall facilities by July 23.
The state has said the facilities in Sylmar and Lincoln Heights are unsuitable for housing, mainly because of staffing issues.
The probation department still has to move about 200 kids in the next nine days.