Containment of the Boulder Fire has been increased to 46% Monday. Size of the fire remains at 233 acres southeast of Mt. Hood on the Barlow Ranger District near Boulder Lake Trailhead. On Sunday, slightly lower temperature and higher relative humidity moved over the fire area. Fire activity was minimal even as winds picked up with the arrival of a cold front. Cary Neu of Northwest Team 10 says crews are about halfway done with mop-up work. Many of the roadways, campgrounds and trails north and east of Forest Road 48 in the Barlow Ranger District are closed. The cause of the fire remains under investigation.