A raging wildfire along the northwest edge of Yosemite National Park is gaining strength Saturday morning as firefighters scramble to protect nearby mountain communities.

The fire held steady overnight at nearly 200 square miles, but a spokesman for the California Department of Forestry and Fire Protection says firefighters didn’t get their usual reprieve from cooler early morning temperatures Saturday.

The Rim Fire started in a remote canyon of the Stanislaus National Forest a week ago and is just 5 percent contained with more than 2,600 firefighters on the lines. A half dozen aircraft are being used to battle the blaze.

The Yosemite Valley, the part of the park frequented by tourists and known around the world for such iconic sights as the Half Dome and El Capitan rock formations and Yosemite falls, remained open, clear of smoke and free from other signs of the fire that remained about 20 miles away.