[1] Von Haast explored a route from Otago to the West Coast that was long known to Māori; his four companions were William Young (a surveyor), Charles Håring (a retired sailor), William Francis Warner (later the proprietor of Warner's Hotel), and Robert Langley Holmes (later the Canterbury provincial meteorologist).

At Pleasant Flat, where the valley widens out, the state highway crosses back to the true left.

[4] The Haast plain extends 50 km (31 mi) from Ship Creek to Jackson Bay / Okahu.

The plain has an unusual landform, with long parallel lines of low hills with narrow swales in between.

The landform results from the combined effects of sediment carried to the coast by six large rivers, longshore drift and periodic seismic uplifts.

The Alpine Fault runs along the inland edge of the plain, and the entire area is subject to tectonic uplift during major seismic events.