Large crowds gather for New Year firework display in Wigan
and live on Freeview channel 276
The Friends of Three Sisters said they received reports of large crowds and a firework display taking place.
The group, who help maintain the wildlife wetland reserve, said that £200 worth of fireworks had been let off.
Ian Winstanley, who is involved with the group, said: "The Friends of Three Sisters received reports of large crowds and a firework display which is illegal obviously.
"The warehouses along the entrance road have CCTV which cover the entrance gate and have been helpful in the past.
"Absolutely illegal and a dangerous gathering."
Mr Winstanley said himself and another volunteer found at least four very large and expensive units with 30 Roman Candle fireworks and 25 rockets of the type used for large events.
He said: "Someone let £200 worth of fireworks off
"Myself and Paul found four or more very large and expensive units with 30 Roman candle and one with 25 rockets, the ones used for large events."
On New Year's Day, he then said that the car parks were full on Three Sisters Road while Kestrel Drive was also packed out near the timber yard right up to Redgate Road.
He added: " Every one was enjoying Three Sisters, hundreds of children were playing in snow and it was the same the day after."