(ZigZag, OR) -- Lightning sparked at least four fires in the Mt. Hood National Forest. The largest fire is the Sandstone Fire on the Clackamas River Ranger District. It's burning on the south side of Thunder Mountain and has grown to 350 acres. Scooper planes are using Timothy Lake and Detroit Lake for water. The other fires are under a quarter acre. The Barlow Ridge Fire is near Highway 35, the Hunchback Fire is contained, and crews are working to contain the Fish Creek Divide Fire.