The wildfire burning in the Pusch Ridge Wilderness area of the Catalina Mountains has grown to about 200 acres, officials said Tuesday.
The fire is burning in rugged terrain and is being allowed to burn to benefit the landscape, officials with the Coronado National Forest said.
The Buster Mountain Fire was ignited by lightning Monday afternoon on Buster Mountain. It's burning grass in steep, rocky terrain that is inaccessible.
Forest officials said while the fire can be seen from homes in Oro Valley and the northwest side, no structures are threatened.
Officials said an incident commander has been assigned to the fire and the fire and weather are being monitored closely.
Also, a smaller blaze is burning in a remote area of Redington Pass east of Tucson. It had burned about 60 acres of grass and brush. No structures are threatened and rain was expected Tuesday evening in the area.