This generalized statewide data set is contoured to display the elevation in feet (relative to mean sea level) of the top of consolidated geologic formations that are older than Quaternary in age. In most locations, the contour depicts the top of consolidated bedrock, however, in some locations (such as the Southeastern Lowlands) the material older than quaternary is poorly consolidated. The material above this three-dimensional surface generally displays different characteristics with respect to load-bearing capacities and ease of excavation than the consolidated bedrock at lower elevations, with higher load-bearing capacities generally occurring in consolidated formations and greater ease of excavation generally occurring in materials above this surface. The contours can be used in a general way to interpret potential problems or lack of problems for infrastructure development. The contours also can be used to interpret areas where thick, unconsolidated sediments in northern Missouri may provide groundwater supplies in preglacial channels.