[1] The underfit stream cuts through terraces of glacial outwash gravels in its course, culminating in a 120-metre-deep (400 ft) incised gorge near to its confluence with the Esk.

[2] The over-wide valley through which Pūkio Stream flows, is due to the presence of an underlying fault depression which once acted as the former course of the Cox River.

[2] The gorge in the lower reaches has been eroded through superficial deposits of glacial origin, and into the underlying greywacke bedrock.

[3] In 2015, Nigger Stream was complained about by a member of the public to the New Zealand Geographic Board (NZGB) for being offensive.

[6] Following a second consultation on the new name which was supported by the Green Party of Aotearoa New Zealand,[7][8] this proposal was passed unanimously by the NZGB however similar proposals in relation to nearby Niggerhead and Nigger Hill were referred to the Land Information New Zealand Minister, Louise Upston.