Abstract: A method for creating a facies probability cube is disclosed. A S-grid containing facies is first created. The grid includes layers of cells and columns of cells. Vertical facies proportion data for the layers of cells is derived from sources such as well data, conceptual vertical geologic sections and graphs describing the proportion of facies found in each of the layers. Areal depocenter maps are created which have defined boundaries to create depocenter regions in which respective facies are likely to occur. Ideally, the boundaries for the depocenter regions for each of the facies are sequentially and independently defined. Horizontal or map facies proportion data are generated for the columns of cells preferably by filtering the depocenter regions so that the proportion of each of the facies ranges from a maximum value to a minimum value.