The sandstone formations could retain groundwater sufficient to make a suitable environment for primitive man. The cliff overhangs offered natural shelters for these early humans. The first human ancestors may have been at Waterberg as early as three million years ago, since Makapansgat, 40 kilometers distant, has yielded skeletons of "Australopithecus africanus". Hogan suggests that Homo erectus, whose evidence remains were also discovered in Makapansgat, "may have purposefully moved into the higher areas of the Waterberg for summer (December to March) game".