Most of the rock comprising Trophy Mountain is part of the ancient Shuswap Metamorphic Complex which arches across the British Columbia Interior in a wide band from Shuswap Lake to Adams Lake and into the Quesnel Highland. No age has been established, but it was intruded by the Raft Batholith about 100 million years ago. The glaciers of the Pleistocene and earlier ice ages have scoured Trophy Mountain creating numerous bowls now filled by lakes and the rugged north face which is high.