From Mueller Glacier

From the Frind-Mueller confluence, ascend part way up the true right edge of the lower Frind Glacier, then climb left along rock ledges to gain the base of the Ngakanohi (‘the eyes’) Glacier above Ngaroimata (‘the tears’) Falls. Traverse diagonally up to the top of the Ngakanohi Glacier and continue around onto the snow shelf below Twain Col and Mt Eric. Climb the steep slope to the col.
Most parties who have crossed the Main Divide in this region have gone over the summit of Maunga Ma instead of Twain Col, as it is generally less steep.