Mount Conner is made up of conglomerates, sandstones, siltstones and mudstones. The summit consists of coarse-grained sandstone with pebble layers and small beds of pebble conglomerate and siltstone. The rock that lies underneath this is composed of dark brown micaceous siltstone, mudstone, and fine-grained sandstone. The lower part of the mountain consists of medium to coarse-grained, grey-brown sandstones, dark-brown siltstones, and cherts. The sides of Mount Conner are also covered by scree (talus) and its top is covered with colluvium. The base of the mountain is surrounded by alluvium.