Abstract: This invention relates to a vehicle-mounted closed circuit portable crushing and screening plant in which a plurality of units for processing material to be crushed, such as a grizzly, a primary crusher, and a secondary crusher are mounted to discharge their outputs onto the horizontal feeder portion of a dual belt conveyor-elevator having an elevator portion which receives the deposited material from the horizontal feeder portion and elevates such material to and discharges such material into the upper feed end of a vibrating screen device mounted on the vehicle. The vibrating screen device classifies the material deposited thereon for recirculation to the secondary crusher and/or for discharge as a plurality of end products of predetermined size classifications. The vibrating screen device and the dual belt conveyor-elevator are both foldable from an elevated operating position to a retracted transport or storage position.