Honolulu fire officials say a brush fire was burning on the ridge above Helemano Estate in Wahiawa Monday afternoon.
The fire was was about an acre in size and was on state land.
Firefighters attacked the blaze with coordinated water drops between aerial units and firefighters on the ground.
Firefighters are working with the Department of Land and Natural Resources and the Department of Forest and Wildlife to navigate the area to gain access to the fire.
There was a brush fire in the same area about a week ago.
Fire officials believe they will likely be fighting to extinguish the brush fire until sundown.