Abstract: The present invention is directed to a drilling rig base and a lower mast section that are collapsible into a compact transportable position. The base is expandable in the field to support a drilling platform and all necessary equipment, and the telescoping mast is also expanable for supporting the crown block and cables of the drawworks. More specifically, the rig of the present invention has a base having a plurality of beams, the outer beams being collapsible to a transportable position for placing on a single truck or trailer, and the A-frame lower mast section which is collapsible to a transportable position for placing on a single truck or trailer.