Stone hand-tools that have been carbon-dated to show they are up to 1500 years old have been unearthed during work for the Pacific highway upgrade north of Coffs Harbour.

Local Aboriginal Land Councils are now working with the Roads and Maritime Service (RMS) to identify and preserve artefacts and significant sites.

Coffs Harbour Aboriginal Land Council chief executive Chris Spencer said there are numerous cultural sites in the Gumbayngirr Country that the highway will run through.

"They range from napping floors to open campsites, middens, saltwater middens and those sort of things which are very special to Aboriginal people and Aboriginal community," he said.

"Particularly the Gumbayngirr People because it gives us an indication of where our ancestors were living and also utilising the landscape for their needs at that particular time."

Mr Spencer said there are a number of artefacts and sites found along the highway route that have great significance for the Gumbayngirr People.

"We were actually given the opportunity to walk the entire route that was selected for the highway," he said.

"It was quite difficult at times, not always having access to private land.

"So we've had to get approvals to be able to enter those private lands.

"But we've been able to do that.

"We're in the process at the moment of doing some archaeological investigations to establish the extent of the cultural sites that are being located."