Do not attempt to climb to and cross Copland Pass unless you have a high level of mountaineering experience and appropriate mountaineering equipment. Climbers have died attempting to cross Copland Pass. Access on the eastern side of the divide is difficult due to erosion. It is strongly recommended that you do not attempt to cross Copland Pass from the west.
There is more information about Copland Pass in Aoraki Tai Poutini: A guide for mountaineers by Rob Frost. It is available for sale at the Aoraki/Mount Cook National Park Visitor Centre or on the New Zealand Alpine Club website.