Around 5,000 people are incarcerated within the walls that surround this square-mile block, west of Lancaster. Mira Loma has a state and a county correctional facilty here. The State's confusingly named Los Angles County prison has a designed capacity of around 1,200 inmates, and generally houses over 4,000. The Mira Loma Detention Center is a Los Angles County facility that primarily holds Immigration detainees for the INS. California's prison population now totals approximately 150,000.