The petition had been the subject of an article on the Daily Mail website, the world's largest news site, and was also featured in Australian, German and Dutch news.
Now, with more than 16,000 signatures, Ms Ko hoped the petition would "pressure the decision-makers" into abandoning the proposed 11.6km tunnel running from Mount Aspiring National Park to Fiordland National Park.
"I knew there was a big protest out there, but I had no idea how people would respond because I have no petition experience.
"I'm so happy with all these different signatures from all over the world, and there's enormous New Zealand support as well, not just from these regions but from the North Island as well."
And with the small Glenorchy community strongly opposed to the proposal, small coloured flags with the message "Stop the Routeburn tunnel" had been created and were waving in constant protest.
The tunnel had an estimated monetary cost of $150 million, but Ms Ko said the bigger cost was the image New Zealand was portraying to the world of the sacrifice of communities and two national parks.
"It affects everybody - the people who visit, the local people who live here, in our daily lives, and everybody in New Zealand - with the image it sends internationally about New Zealand."
The petition gained more than 4000 signatures in just over three weeks and Ms Ko presented it to Conservation Minister Kate Wilkinson at Queenstown Airport as the minister was departing after attending the Trenz tourism expo.
After six weeks and 11,500 signatures, the website hosting the petition revealed Ms Ko's petition was the largest it had hosted in New Zealand.
Communications director for change.org New Zealand and Australia Tony Robertson said the tunnel debate was "one that clearly resonates with people".
Ms Ko, who has no plans to take the petition off the website, was now waiting for the minister to make a final decision on the future of the tunnel proposal.
