Onnum Valley is an ice-free valley between Derrick Peak and Onnum Ridge in Britannia Range. Named in association with Onnum Ridge by a University of Waikato (N.Z.) geological party, 1978–79, led by M.J. Selby.
This article incorporates public domain material from the United States Geological Survey document "Onnum Valley" (content from the Geographic Names Information System).
References
Onnum Valley Wikipedia(Text) CC BY-SA