Mount Conner is a flat-topped inselberg, shaped like a horseshoe. The rock is sedimentary. Its layers were left behind when the area was an inland sea, during the Neoproterozoic era (1Ga to 542Ma). The rock of Mount Conner is 200 to 300 million years older than the rock of nearby Uluṟu and Kata Tjuṯa. The younger layers of sedimentary rock eroded over millions of years leaving the inselberg that is seen today.