The state chose two sites in Imperial County for new prisons that will house 4,400 inmates. The new prisons will be near Calipatria in the central part of the county and near Mt. Signal in the southern part, Corrections Director James Rowland said. The state already has legislative authorization for a $208-million, 2,200-bed maximum-security institution near Calipatria, Rowland said. The department will seek legislative authorization for the second site, a 2,200-bed medium-security facility, to be funded from a 1990 prison construction bond issue, Rowland said.