From June 17–20, 1974, Americans Roman Laba and John Thackray climbed the northwest ridge of Huayna Potosi. The AAJ 1975 feature describing this climb is erroneous in recording it as the northeast ridge. The only reference to an earlier ascent of the northwest ridge attributes it to Hans Ertl in 1972. This is not only unconfirmed but is extremely unlikely for a number of reasons, not least because Ertl had given up climbing before then. Laba and Thackray’s climb is the first confirmed ascent of the northwest ridge.

Laba climbed two more routes on Huayna Potosi: the west ridge in 1969 with John Hudson, a first ascent (and always correctly identified as such), and a 1976 repeat, with John Roskelley and Jim States, of the 1970 American Route on the west face.

Laba and Thackray also made the first ascent of Illimani’s south face in 1974. Recent AAJs have reported new routes on the south face but repeatedly failed in photodiagrams to note the first route. This ascent took place in early July 1974 when Laba and Thackray climbed a line more or less in the center of the face. As their approach to the face and the climb itself were carried out in very poor visibility, the line cannot be identified exactly, but it started on the left side of the broad buttress in the center of the face. It is likely unrepeated. 

– Lindsay Griffin, after discussion with Roman Laba and John Thackray