A forest fire rages near Ulster County, NY on May 5, 2015. (credit: Delaware County Emergency Services)

SUMMITVILLE, N.Y. (CBSNewYork/AP) – A fast-moving wildfire at the southern edge of the Catskill Mountains has forced some homeowners to evacuate.

The fire, which started just before noon on Sunday in the Town of Mamakating, has affected more than 2,400 acres of the Shawangunk Ridge and Roosa Gap state forests, said Jim Hay with the state Incident Management Team.

The Ulster County Sheriff’s Department asked some residents in the Cragsmoor area to play it safe and leave their homes.

Forest Fire Near Ulster County A forest fire rages near Ulster County, NY on May 5, 2015. (credit: Delaware County Emergency Services)

Forest Fire Near Ulster County A forest fire rages near Ulster County, NY on May 5, 2015. (credit: Delaware County Emergency Services)

Forest Fire Near Ulster County A forest fire rages near Ulster County, NY on May 5, 2015. (credit: Delaware County Emergency Services)

Forest Fire Near Ulster County A forest fire rages near Ulster County, NY on May 5, 2015. (credit: Delaware County Emergency Services)

Ulster Forest Fire A fire ripped through the Roosa Gap Forest and the Shawangunk Ridge State Forest in Sullivan and Alster counties on Monday, May 4. (Credit: CBS2)

Sullivan County safety officials say more than 20 fire companies are trying to prevent the fire from spreading as they work to extinguish the flames. It is also being fought from the air.

“The terrain of where the fire is, is extremely hazardous,” Hay told WCBS 880’s Peter Haskell reported.