This dataset includes polygons that describe areas of rock outcrop in the area of the Stillwater Complex, Montana. The Stillwater Complex is an Archean, ultramafic to mafic layered intrusion exposed in the Beartooth Mountains in south-central Montana. This igneous intrusion contains magmatic mineralization that is variably enriched in strategic and critical commodities such as chromium, nickel, and the platinum-group elements (PGE). Polygons representing rock outcrops were digitized in a Geographic Information System (GIS) using georeferenced maps and orthophoto imagery from published reports and field mapping sheets. This is a compilation of both legacy data and outcrops from recent field mapping. This dataset contains overlapping polygons, as some areas had mapping from different sources that overlapped the same locations.