Opponents of large-scale lignite mining in Southland gathered in Mataura over the weekend to present their case to the community.
The "keep the coal in the hole summer festival" drew more than 100 people who camped on a farm bordering Solid Energy land.
The company has started construction of a $25 million briquetting plant and wants to expand that into a two-billion dollar diesel and urea facility.
But the Coal Action Network, which organised the weekend, says people should be wary when dealing with Solid Energy.
A Queensland farmer, brought over by the network, says he fought a big mining company when it opened an open cast mine next to his property.
He said well-resourced companies will stop at nothing to get what they want.