Abstract: The invention comprises a forage trailer. The trailer has an upper and lower frame with a scissor mechanism to raise and lower the upper frame. The lower frame has wheels thereon for towing. The upper frame has a box pivotally mounted to one side of the upper frame with hydraulic cylinders to pivot the box from horizontal to an angle. The box has one side wall in the direction of the pivoting action which opens up automatically to allow materials within the box to be emptied from the box while pivoted through the opening in the side wall of the box. The opening automatically closes when the box is pivoted back to horizontal.