Pictograph Cave excavations, Billings, MT ID: 4964 | This file appears in: Pictograph Cave View of Pictograph Cave WPA crews during initial excavation efforts. | Creator: Unknown photographer | Date: ca. 1939 | Source: Montana State Historic Preservation Office, Helena, MT. Download Original File CreatorUnknown photographerSourceMontana State Historic Preservation Office, Helena, MT.Dateca. 1939 "Pictograph Cave excavations, Billings, MT" appears in: Pictograph Cave