A new method has been developed for building and visualizing three-dimensional (3-D) subsurface natural fracture networks in rocks surrounding boreholes using image logs, such as CAST, EMI, FMI, FMS, ROSI, and others. The method correlates fracture patterns with different stages of fracture network development for individual sets of fractures and extrapolates fracture density and connectivity from one dimension (1-D) in boreholes to 3-D in the surrounding rocks. The application of this work is 3-D visualizations of fracture distributions in volumes close to the boreholes for well planning, reservoir-scale fracture model building, reservoir flow simulation, and hydraulic fracture control.