The boundary to Canterbury was defined as the crest of the Southern Alps / Kā Tiritiri o te Moana.

Members of Parliament were not happy with having to spend their time on local legislation, and in 1873 the government elevated the county to full provincial status – the last of the 10 New Zealand provinces to be established.

[1] The province covered an area roughly the same as the present day Westland District, on the West Coast of New Zealand.

Bonar was chairman during the period of the Fenian riots and is credited with "great tact in handling that explosive situation".

Bonar was replaced by Conrad Hoos, but later—when on 1 December 1873 Westland split from Canterbury Province—Bonar resumed, but as the provincial superintendent.