The fires were put out just a day after the Third Army Area deployed troops to help fight the blaze and deter local villagers fom setting new fires in the vast national park.
The helicopters were credited with playing a huge role in helping park officials, troops, volunteers and locals to put out the blazes.
The two choppers were dispatched from the Disaster Prevention and Mitigation Department of the Interior Ministry and from the Natural Resources and Environment Ministry just three days ago.
On Monday, they flew several sorties to draw water from Huay Sapaed reservoir in neighbouring Chom Thong district, dropping the loads on the advancing edges of fires fed by dry leaves and branches in Ob Luang park.
Chiang Mai governor Nirat Pongsitthavorn and deputy governor Thossapol Puan-udom took charge of the firefighting operation throughout Monday night before declaring success on Tuesday.
Kritsayam Kongsatree, chief of the 16th protected zones administration office, said firefighters would continue to watch over the area in case the blaze rekindled or villagers attempted to set more fires.
On Tuesday morning, Nirat led a team to deliver supplies including energy drinks to the firefighters and thank them for their hard work.
The governor said officials would remain vigilant in areas at risk of catching fire.
He said local villagers would be asked not to go into forests to forage for food for fear that they would start new fires.