Eight members of Queenstown's Czech & Slovak Club walked part of the track on Friday and Saturday to install the plaque for Ondrej Petr.
The 27-year-old died on Ocean Peak, near Lake Mackenzie, on July 28 after he and partner Pavlina Pizova became disoriented in bad weather and deep snow.
Honorary consul for the Czech Republic Vladka Kennett, of Glenorchy, said the plaque was placed at a point known as Ocean Peak corner, where the track begins to descend to the lake.
``It was quite moving.''
They had found themselves imagining what it was like for the couple as they tried to cross the terrain in waist-deep snow during midwinter.
``We reflected upon the fateful trip of Pavlina and Ondrej, trying to rationalise their thoughts and decisions.''
The couple's families and club members hoped the plaque would serve as a reminder to people to ``always respect the mountain environment of New Zealand'', Mrs Kennett said.
The group, which spent Friday night at Routeburn Flats Hut, was lucky with the weather, as heavy rain held off until their return to Glenorchy.
Following Mr Ondrej's death, Ms Pizova spent two nights in the open and was rescued after spending 24 days alone in the Lake Mackenzie warden's hut.