A DoC spokesman said bait was laid over the ants' colony at Rarawa and the camp was closed down for three weeks while it took effect.
It reopened last week.
"The camp has again opened and it's already full of campers for the Christmas period," the spokesman said.
Auckland Council Hauraki Gulf biosecurity adviser Brian Shields said when campers moved to other camp grounds, the ants often hitchhiked in their trash, which they were required to take with them at Far North sites.
Shields took his old mate Rhys Jones Up North to ensure the rest of the region's campsites were ant-free.
"We went around and surveyed the rest of the sites in the area and Rhys gave them the all clear," he said.
Rhys Jones, a Welsh springer spaniel, has been trained to identify the signature scent of the Argentine ant, and his nose is so sensitive it can ignore native ants and hone in on the invader species.
"He's a cool dog and he loves getting out there and doing his work," Shields said.
Despite Rhys and Shields' tireless efforts, the number of Argentine ant colonies continues to rise.
"We're doing a good job keeping them out of the Hauraki Gulf islands, and DoC are doing a really good job stopping the spread as well, but people have got to be very, very aware because they can spread so easily.
"They love things like potting mix so if you take your pot plant up to your batch you can easily transport them that way, because you basically only need a queen and a few workers to start a nest."
