1. The document discusses the prehistoric archaeological sites found in the Ganga Valley region of Uttar Pradesh and Bihar, including rock art sites in the Kaimur hills. 2. It summarizes excavations that have uncovered artifacts from the Middle Paleolithic through Chalcolithic periods, indicating human habitation in the region dating back 100,000 years. 3. The document analyzes the geo-ecology of the region and suggests that the early inhabitants who occupied sites like Koldihwa and Mahagada during the Neolithic would have been the authors of the rock art found in the numerous rock shelter sites across the Kaimur hills.