HARDWICK — As the sun set late Monday afternoon, state forest fire officials said the fire burning on the side of Mount Tammany was 80 acres in size and 80 percent contained.


Christopher Franek, assistant division forest firewarden, who has been overseeing the effort to contain the fire which broke out Sunday afternoon, said the fire crews were being scaled back for overnight and expected the fire would burn itself out.


A fire line, meaning crews had removed most combustible material, had been established around the fire and with the forecast rains for today, there was little danger of the fire spreading.


He said there were 51 firefighters from the state Forest Fire Service and federal agencies including the National Park Service and U.S. Fish and Wildlife Service involved in Monday’s efforts.


The fire remained within the boundaries of the Worthington State Forest and had not spread to property of the Delaware Water Gap National Recreation Area. However, top firefighting officials with the NPS were involved in the planning.


Franek said investigators had a general idea of where the fire began, but was unlikely to pinpoint the exact cause. He said there was no physical evidence, such as remains of a campfire or bottles, found.


The National Park Service bans open fires on its property while the state forest allows open fires only within the campgrounds which are on the banks of the Delaware River away from where the fire began.


While crews were fighting the fire in Hardwick, other members of the Forest Fire Service and local volunteer firefighters responded to a couple of reported brush fires in Sussex County on Monday.


Franek said responding units were able to quickly contain those fires, including one on Wantage Avenue in Wantage, within a quarter-acre.


In addition to manpower on the ground, Monday’s efforts on the side of Mount Tammany involved a helicopter which dropped water from a large canvas "bag" suspended below the aircraft. With that technique, crews on the ground can get water dropped directly on the fire or to wet down an area to slow down or halt the fire’s spread.


The National Weather Service forecast for Tuesday through Thursday calls for on-and-off rain with the heaviest Wednesday night. The forecast is for as much as an inch to fall through Thursday.


The region has seen less than half the expected precipitation for an average February with well-above temperatures. Under near cloudless skies on Sunday, the daytime high reached 54 degrees and Monday’s high was 59 degrees, as recorded at the Andover Aeroflex Airport. Record high for a Feb. 24 in Newton is 68 degrees in 1865.


The firewarden said that in a normal February year two to three feet of snow would be on the mountain side and that this is unusual for brush and forest fires in February.


He said the firefighters are using shovels, blowers and specially-designed mattocks to control the blaze. He said they also set their own controlled burns to create a burned area to stop the fire’s spread.


Franek said the fire was being fueled by leaf litter and "dead and down fuel," especially dead hardwoods which were killed by gypsy moth caterpillars in past years.


He said some of the areas burning are inaccessible because of the rock ledges that make up the mountain.