Department of Conservation Wakatipu area manager Greg Lind is confident the "idiot" who tagged various structures the length of the Routeburn Track last month will be apprehended and prosecuted.
Mr Lind said yesterday about 40 felt pen tags featuring the word "Rowdy" had appeared on wooden and painted structures along the 32km track.
It was the first time anyone had vandalised the track, one of New Zealand's Great Walks, which is located in the Fiordland National Park, a World Heritage Area.
The same tag had also appeared in Franz Josef and at Wanaka, he said.
The person responsible could be charged under the National Parks Act 1980 with wilfully damaging or defacing a fence, building or apparatus; or unlawfully altering, obliterating, or defacing signs and marks, including boundary marks.