The pass sits 920 metres or 3,020 feet above sea level and marks part of the boundary between the West Coast and Canterbury regions.

The reason for making this difficult journey was greenstone (pounamu), highly prized both for its hardness and beauty and found only on the West Coast of the South Island.

[2] In 1860 writer and explorer Samuel Butler had seen a pass at the head of the Bealey Valley, but was travelling alone and did not want to leave his horse unattended so "shirked investigation".

The provincial engineer, their father Edward Dobson, was commissioned to examine every possible pass to the West Coast from the watersheds of the Waimakariri, Taramakau and Hurunui Rivers.

[4] The provincial government decided that a road was to be built between Christchurch and Hokitika, a distance of 156 miles (251 km), and Edward Dobson was put in charge of the project.

The Arthur Dudley Dobson memorial, a stone column of 25 feet (7.6 m) in height, was unveiled in April 1937 at the alpine pass that bears his name.

Previously prone to be blocked by landslides or avalanches, the road on the western side of the pass has seen extensive civil engineering work in the late 1990s.