A single lane has opened to traffic on State Highway 25 at Ruamahunga Bay in the Coromandel.
The major road north of Thames had been shut off by debris that fell during bad weather last weekend.
A speed restriction of 30km/h is in place and drivers are being told to take extreme care.
The Transport Agency says the slip's size made it difficult to clear the site as quickly as hoped.
About 12,000 cubic metres of earth was moved by the slip.
