A four-alarm fire burned up to five acres of brush at the Stony Brook Reservation in Hyde Park, officials said.
The Boston Fire Department and Department of Conservation and Recreation have stopped the fire from spreading and are working to fully extinguish the flames, said Chief Fire Warden Dave Celino of the Bureau of Fire and Forestry.
"The fire is in some of the most rugged terrain," he said. "It's going to be manpower-draining. It's in an area that's inacessable."
It is not known at this time if any people were injured in the fire, Celino said.
Enneking Parkway, which runs north-to-south through the reservation, is closed between Rev. Paul A. Phinn Way and Dedham Parkway, DCR posted on Twitter.
Celino said brush fires typically happen beacuse of dry leaves, warmer temperature, and vegetation that hasn't yet bloomed.
"All of those influences come together to create very easy ignition," he said.
The cause of the fire has not yet been determined, Celino said, but over 95 percent of all wildfires are caused by people.
In 2015, there were 2,541 wildfires in Massachusetts that burned a total of 2,381 acres, Celino said.