Abstract: A hard cover for the open bed of a pickup truck is thermoformed from two sheets of heat deformable plastic material. The top sheet has a slightly crowned surface and four depending walls defining a perimeter lip corresponding to the top ledge of a pickup truck bed. The bottom sheet reinforces the top sheet and is itself slightly crowned and includes four walls. The bottom sheet includes prop support members which depend below the margin defined by the perimeter lip of the hard cover. The perimeter lip of the hard cover may be adapted to reside within a range of similarity sized pickup truck bed rail margins, so that one hard cover can be utilized on several truck models. The hard cover may also be associated with a molded platform that overlays and closely conforms to the bed rails of a truck bed to provide a protective truck bed cover assembly. The molded platform is provided with a channel to receive the lip of the hard cover to provide a seal.