Emergency services have asked onlookers to stay away from fires as police investigate the blazes that threatened homes and factories around Thurgoona on Tuesday.
Fire and Rescue NSW Inspector Frank Finlay said the cause was still unknown for two of the three fires which burned near the Murray Park estate and Thurgoona industrial area.
"It has been handed over to the police to carry out investigations into the causes of the fires," Mr Finlay said.
"The secondary fire that crossed Elizabeth Mitchell Drive was due to spot fires due to the winds pushing through."
Mr Finlay asked people to keep out and not hamper the work of firefighters during emergencies.
"When we're out on a fire, every minute counts."Frank Finlay, Fire and Rescue NSW Inspector
"When we're out on a fire, every minute counts," he said.
"We had to close a lot of roads due to onlookers.
"Trucks take a lot to slow down compared to a car and they also take a bit of time to speed up again.
"It makes it very hard for firefighters to get through and it's also dangerous because we have firefighters on the roadways and so they've also got to look out for people standing around watching."
Lavington's Rural Fire Brigade's Bruce Barnes attended the fire and echoed a similar statement.
"There were too many people coming in," Mr Barnes said.
"They're making it hard for firefighters to actually gain access.
"If something goes wrong then we've got to deal with all these people in there."
Mr Barnes instead urged people to see firetrucks and firefighters at the Lavington Rural Fire Brigade Christmas light display from next week.
"We mainly do it for awareness and to let people know where we are and what we're about," he said.
Mr Barnes said with the fire season well under way, it was important for people to know how to be safe and he welcomed potential new recruits to the service.
Mr Finlay said the grass fire was the biggest urban fire he had seen in the last 18 months with between 50 and 60 Murray Park homes evacuated.
"It was a large threat, but due to the fast response of firefighters no lives were lost," Mr Finlay said.
No houses were lost to the fire, although damage to multiple cars and a trailer was reported.
The fires burned a total area of about 25 hectares from Elizabeth Mitchell Drive to Table Top Road.
A team effort of Rural Fire Service crews from as Walla, Fire and Rescue teams from Corowa and a Country Fire Authority crew from Wodonga attended the scene.
Crews worked for about seven hours after receiving multiple triple zero calls, mopping up until 10pm on Tuesday.
Patrols continued on Wednesday morning.
RFS's Andrew Gray asked people "to help us help themselves".
"Its important for people to make sure they've removed long grass and flammable fuels," Mr Gray said.
"We ask that they clean up their yard and make sure they don't have any flammable material in reach of structures.
"If you've got long grass all around your boundaries it's only going to increase the risk for fires."
More information on how to prepare houses for the fire season can be found on the RFS website.