Aeromagnetic data are analyzed to study the configuration of the Precambrian rocks in the eastern Paradox basin [Utah-Colorado], principally in the vicinity of the Gypsum and Dolores structures. The analysis shows that the Precambrian surface is uplifted several thousand feet on the southwestern flanks of the surface structures and that the uplifted Precambrian blocks are strongly mineralized ferromagnetically. It is postulated that this mineralization is contemporaneous with deformation that, in turn, resulted in the formation of the "salt anticlines" in the adjacent deep basement areas to the NE. Gravity anomalies in the area are found to be entirely minimal and attributable to the masses of the salt "bulges" within the surface anticlines. These masses are quite well defined in the instances of these structures from the width of outcrop at Gypsum and from the depth to the Precambrian computed from the aeromagnetic data, the pre-salt Paleozoic interval being quite uniform.