State-owned coal miner Solid Energy is denying the public access to a 480ha area around a Stockton Mine development on the West Coast.

It said trespassers face arrest and prosecution.

The coal miner today packed up an unoccupied campsite set up by the protest group Save Happy Valley Coalition. The campsite is in the new exclusion zone.

The miner removed the protest group's equipment on a helicopter and said it could be collected from Westport police station.

The public exclusion zone is being advertised and signs will be placed on a track from Burnetts Face in the south on the route used by protesters.

Solid Energy said it put the exclusion zone in place so preliminary work can start on the Cypress extension of the Stockton opencast mine. This extends the mine's operational area to the east into the Upper Waimangaroa.

The miner plans to extract five million tonnes of coal from the Cypress pits over ten years. The first coal is expected to be extracted from the northern Cypress pit in late 2011.

Solid Energy said it is putting the public exclusion zone in place now so it can collect data for an environment monitoring programme required to meet its resource consents.