[2] Explorer Thomas Brunner, who was the first European to travel up the river to its source, spelled it "Kotu-urakaoka" in the proclamation that in 1853 defined the provincial boundaries.

[3] In 1859 surveyor John Rochfort and his men arrived at the opposite shore of the lake, which he proceeded to name after Brunner.

They made a canoe from a hollowed-out kahikatea log and paddled across the lake to where flowed into the Kōtukuwhakaoka, which Rochfort named the "Arnould River".

[3] Rochfort attempted to survey the "Arnould River" by canoe, but it was choked up with logs and snags, and the party eventually abandoned their vessel for "dreary marches in the midst of drenching rain.

No bridge was built, until in 1990 as part of New Zealand sesquicentennial celebrations Fletcher Challenge and the Department of Conservation collaborated on the construction of a 83-metre footbridge, which took 15 weeks to build, opening on 15 September 1990.