A geostatistical method has been developed by Ontario Power Generation to enable creation of 3D fracture network models (FNMs) that explicitly honor detailed information on surface lineaments. This approach provides a systematic and traceable method that is flexible and that accommodates data from many different sources. The detailed, complex and realistic models of 3D fracture geometry produced by this method serve as an ideal basis for developing rock property models to be used in flow and transport studies. These models are probabilistic in the sense that they consist of a family of equally likely renditions of fracture geometry. Such probabilistic models are well suited to studying issues that involve risk assessment and quantification of uncertainty.