The mountains in Arthur's Pass National Park are part of the Southern Alps that have been created through uplifting, tectonic forces between the Indo-Australasian and the Pacific plate. The mountains in the park do not exceed 2300 m.
Arthur's Pass is famous for U-shaped valleys that are a product of ancient and still ongoing glaciation. Most of them were formed during New Zealand's last ice age, the Otira Glaciation. Lake Sally, Anna and Mavis as well as the Otira and Waimakariri River are the remains of this most recent glacial period that occurred between 10,000 to 80,000 years ago. Other landforms in Arthur's Pass include rocky elevations, massive moraines and flat riverbeds. Major rock types are grey sandstone and argillite - a dark and fine-grained sedimentary rock, containing fractions of silt and clay. Arthur's Pass is also known it's gold and pounamu (greenstone) deposits.
Mount Rolleston (2271 m) is the highest peak in the park and home to the South Island's northernmost glacier (Crow Glacier). The park's largest glacier is Marmaduke Dixon near Mount Wakeman and covers an area of nearly 22,500 ha. The region is part of the Alpine Fault and frequently experiences minor earthquakes that could cause rockfall hazards. The last major earthquake (5.5) occurred on May 29th, 1995. The largest most recent recorded earthquake had a magnitude of 4.1 in March 2017.