Grace Hughes (nee Johnston), her daughter Glenda Alexander and granddaughter Millie Alexander on Saturday unveiled a plaque, organised by the Engineering New Zealand Otago Engineering Heritage Chapter.
The highest suspension bridge in New Zealand, it spans 96m across Skippers Canyon, 91m above the Shotover River.
It was designed by Lake County Council engineer John Black and constructed by Naseby contractor AJ Fraser & Company between 1898 and 1901, to serve the gold-mining settlement.
Eliza Johnston's great-great-great-granddaughter Millie Alexander, now a structural engineer working for WSP Opus in Dunedin, gave a speech at the plaque unveiling.
"Construction wasn't without its holdups," she said, "... with a variety of issues arising, including to quote `the faulty nature of the rock', which meant that the design of the anchorage foundations on the south side had to be altered significantly".
"Despite this, it was reported that Mr Fraser and his team carried out the work well and faithfully," Ms Alexander said.
The bridge is constructed from ironbark timber trusses and birch decking. It has seven steel wire cables each side and 12m concrete piers at each end.
It was officially opened by James McGowan, minister of mines. Mrs Johnston cut the ribbon, broke a bottle of Champagne over the bridge and accompanied the minister on the first walk across, on March 29, 1901.
Mrs Johnston and her husband Samuel were well known in the Skippers settlement, owning the Otago Hotel, which had the township's only telephone, and running the local post office and bakery. They had seven children and Mrs Johnston lived to the age of 85.
Mrs Hughes wore her great-grandmother's gold and quartz brooch to the unveiling.
Engineering Heritage Chapters around the country meet regularly to record preserve engineering structures worthy of heritage status and meet quarterly in Wellington to discuss and promote engineering heritage.
The purpose of its plaques is to record a significant engineering work or structure and provide information to the public with links to where they can find more information.
The Skippers plaque was fitted into place by Lindsay Breen, of Breen Construction.
