From the true right of the Wilberforce River, cross to the true left of Unknown Stream where it abuts
bluffs and follow it along the straightforward lower reaches. About 4 km beyond Unknown Hut the
river forks, the northern branch draining Unknown Col and the south branch draining a rugged section
of the Rolleston Range. Travel up the north branch follows a narrow valley, subject to rock fall,
which has three waterfalls part way up. Negotiating the third waterfall requires a rock climb on the
true right. This waterfall has turned some parties back and a rope may be needed. In early season the
waterfalls are buried in avalanche debris and travel is straightforward.