The paper describes a workflow (and a resulting 3D geological model), developed for detailed 3D modeling of coal deposits in the "Knurów-Szczyglowice" Underground Coal Mine in the Upper Silesian Coal Basin The model covers 20 sa. km (4 × 5 km) and integrates data from various sources mainly coal seam mining maps and lithological borehole profiles, but also auxiliaiy sources like legacy cross-sections and structural maps. High grid resolution and relatively small uncertainties allow future testing of the model's application in industiy-related issues such as mining subsidence prediction or underground coal gasification.