It is known for its small railway station which was the subject of the 1936 painting Cass by Rita Angus, voted in 2006 New Zealand's favourite work of art.

[1]: 7 The topography of the Cass area was formed by repeated glaciation in the Pleistocene, with the valley floor built up by river fans as the glaciers retreated and the nearby Lakes Sarah and Grasmere enclosed by moraines and ice-eroded rocks.

[1]: 79–81 The Ōtira Gorge route was used by Māori travelling from Canterbury to Westland, and there are traces of forest fires and moa hunting in the area approximately 600 years ago.

[1]: 23 After the prime grazing land on the Canterbury Plains had been settled by European colonists, settlers looked for open country in increasingly-remote mountain valleys.

[1]: 29 The coach route led to the construction of stables, a hotel, a police post, and a Road Board office (which later contained the Upper Waimakariri Book Library).

In 1873 what was then Canterbury College was granted over 64,000 acres of land in the area as an endowment, which it then leased out to runholders at Craigieburn, Flock Hill, and Avoca on 21-year terms.

As of 2024 Cass had just one resident: Barrie Drummond, a railway worker who moved there around age 40 and spent over 25 years subsequently as an employee of KiwiRail, performing switching and track maintenance.

Drummond is also the organiser of the annual "Cass Bash", a weekend cricket match each November between locals and representatives of Kiwirail that attracts around 250 visitors.

Charles E. Foweraker undertook the first Honours research project there, and his 1915 photographs of the area are valuable sources of information for vegetation change over the succeeding century.

[1] Other important photographs of the field station were taken by Ellen Heine and are held at the National Museum of New Zealand Te Papa Tongarewa.

In May 1936 Christchurch artist Rita Angus took the three-hour train journey to Cass, accompanied by painters Louise Henderson and Julia Scarvell.