Army firefighters are still battling a wildfire at the Makua Military Reservation that began Friday.

As of 6 p.m. Monday, U.S. Army Garrison Hawaii spokesperson Michael Donnelly said that the fire had grown to 165 acres and was 65% contained.

“They’re going to improve the containment line until sunset tonight,” said Donnelly, who noted that rain is in the weather forecast, which officials hope will aid them in the firefighting effort.

Six firefighters, two fire engines, two UH-60 Black Hawk helicopters and a contracted helicopter have been involved in the firefighting effort.

The fire began at about 12:30 p.m. Friday near the south ridge of the reservation. Army firefighters responded to the blaze and called on the Wheeler Army Airfield-based 25th Combat Aviation Brigade for support. Army aviation support has dropped more than 120 buckets of water on the fire totaling more than 72,000 gallons of water.

There were no units conducting training at the time the fire began, according to the Army. The cause of the fire is still under investigation.

The valley has several ancient Hawaiian cultural and archaeological sites and is home to several endangered species.

“We’ll know more, but there’s no indication that there’s any threat to endangered species or any cultural sites at this point,” said Donnelly.

The Army’s use of the land as a training ground has been controversial. The Makua Valley is sacred to Native Hawaiian cultural practitioners. In the Hawaiian oral tradition, the valley is the birthplace of the Hawaiian people.

A 1998 lawsuit on behalf of the group Malama Makua — which has fought to evict the Army and return the land to Hawaii —brought a halt to live-fire exercises there with none being conducted since 2004. Under a 2002 court- sanctioned agreement, the Army and Malama Makua have cooperated for regular cultural access days to visit sites around the valley open to members of the public who sign up in advance.

In March, U.S. Rep. Kai Kahele announced that he had introduced the Leandra Wai Act — named in honor of the late Malama Makua co-founder — which would require the Army to remediate Makua Military Reservation and return the land to Hawaii.