The Milli Fire burns near Sisters in August 2017.

The Milli Fire near Sisters is burning westward in the Three Sisters Wilderness, fire managers said Tuesday morning.

The fire, first detected almost two weeks ago, has grown to 11,236 acres. Residents of several neighborhoods on Sisters’ west side have been evacuated, while residents of the Tollgate subdivision and Black Butte Ranch have been advised to be prepared for a possible evacuation.

No structures have been destroyed by the fire.

Monday, the Milli Fire was most active on the north side of Black Crater and was observed burning downhill near Lava Lake camp and North Matthieu Lake, all in the Three Sisters Wilderness. The eastern flank of the fire has been more subdued, but fire managers cautioned prevailing wind patterns could push the fire north out of the wilderness area and east toward populated areas.

Fire managers are reporting the fire is 23 percent contained, with 765 firefighters on hand helping to battle the blaze.

Fire officials plan a public meeting at 6 p.m. Tuesday at Sisters High School, 1700 McKinney Butte Road, to update residents about the status of the fire, closures and evacuations.