Abstract: A tonneau cover is mounted to the cargo area of a pickup truck by a hinge mechanism positioned at the forward end of the pickup truck cargo area. The hinge assembly has two major components. The first component is a mounting plate that is affixed to each sidewall of the cargo area near the forward extent of the cargo area. The mounting plate includes an alignment mechanism and a mechanism for clamping the second component onto the mounting plate. The base plate also includes slots for engagement by the clamping mechanism of the mounting plate. The articulating mechanism is configured to open the tonneau cover in a nearly vertical direction initially, prior to rotation of the tonneau cover to an open position. An installer can reach in from the side of the truck cargo area and engage the clamps to secure the removable component to the mounting plate.