The Nenthorn camp was a ''bit of a rough town'' established in 1884 when the railway was built, Heritage New Zealand spokesman heritage adviser media and marketing John O'Hare said.
Once home to Irish, Scots, English, Italians, Polish and Chinese labourers who built the section of railway between Flat Stream and Sutton, it was now ''bare tussock-land'' on Lone Star Farms Barewood Station, near Middlemarch, Mr O'Hare said.
But below the surface, ''evidence of Nenthorn camp's boisterous history'' remained, he said.
Three archaeological digs at the site were done about two years ago by the University of Otago's archaeology programme, under the leadership of Tim Thomas, and various features uncovered.
The remains were then analysed by the university team over another year and a report recently given to station management.
Now the areas have been fenced off to protect them from stock and other possible damage.
Another area where a water wheel was operating will also be fenced off to protect it for future generations.
The archaeological features have also been included in the farm's environmental plan.
The project was a ''great initiative'' on the part of station manager Marty Deans and owners Tom and Heather Sturgess, and would protect an important example of colonial New Zealand archaeology, Mr O'Hare said.
''It's great that these archaeological features will be protected in this way.
''The owner should be congratulated for his commitment to preserving the archaeological heritage of the site.''
Mr Deans said he was pleased the historic features would be protected and the findings of the archaeological digs were fascinating.
