Abstract: A dump truck bed cover and positioning mechanism which is actuated from within the cab of the truck and which eliminates the need for complex roller mechanisms. The device includes a flexible cover, the cover being affixed at one end to the forward bed of the truck, a cover windscreen, a bail having a cross-member connected to the free end of the cover and a pair of arms connected to an actuating rod which pivots the bail from a first position to a second position for covering or uncovering the load bed of the truck. The lateral sides of the cover are slidably connected to cover retaining lines which hold the cover to the bed in the covered position. In the open position, the cover is stored with a plurality of folds behind the windscreen at the forward end of the bed. A tensioning arm is connected to one end of each of the cover retaining lines to provide proper slack or tensioning of the lines.