Upper Spencer Gulf leaders were treated to a first-hand visit to OZ Minerals' Carapateena copper-gold mine, about 160 kilometres north of Port Augusta.
Mayor Leon Stephens and Port Pirie Regional Council chief executive officer went on the trip with Whyalla Mayor Clare McLaughlin and chief executive officer Chris Cowley and Port Augusta Mayor Brett Benbow and chief executive officer John Banks.
It was hosted by OZ Minerals earlier this month.
Mr Stephens, who is chairman of Spencer Gulf Cities, said the visit really put the project into perspective.
"We were just blown away by the extent of the operation. The facilities are amazing," he said.
The strong focus on local procurement and workforce was a key feature for the mayors.
Whyalla Mayor Clare McLaughlin said she was happy to see the company was prioritising local employment and local procurement.
"With the jobs growth opportunities expected from construction through to production on the Carrapateena project in coming years, it will provide a tremendous boost for our three cities and for the state," she said.
The mayors commended the company's approach to community engagement and maximising the local benefit from the project.
"Right from the start, OZ Minerals has been genuine in its engagement with our communities and demonstrated a strong desire to do the right thing by us. We really appreciate that," said Port Augusta Mayor Brett Benbow.
Mr Stephens agreed, saying the company was a great model for other developers.
"Having a social licence is more than just ticking a box. OZ has consistently demonstrated it is serious about working with us so that we all win."