[1][4] The lake is between the peak of Tautoro to its east which raises to 463 m (1,519 ft) and the volcanic scoria cone of Tauanui to its northwest.

[4] Analysis of lake sediments suggested it formed about 5500 years ago.

The area was likely affected by local volcanic events and pollen studies showed surrounding rimu dominant mixed conifer-hardwood forest also containing kauri.

About 4000 years ago the climate became cooler and drier with fire in the lake's catchment and from then to about a thousand years ago there was more fluctuation in the forest species present than before.

Fires were more common and after the arrival of Europeans, herb pollen increased markedly.