Containment grew overnight on a fire burning for more than a week in Yosemite National Park and residents of the community of Wawona can return to their homes starting Sunday, park officials said Saturday.

The Washburn fire was 37% contained, up from 27% Friday, and grew slightly to 7.5 square miles (19 square kilometers).

“Yesterday we had a very successful day and it was the day we were waiting for,” said Matt Ahearn, operations section chief in a Saturday morning briefing.

The fire started July 7 and is now burning in the Sierra National Forest. How the blaze began remains under investigation but officials suspect people were the source.

Yosemite National Park visitors are prohibited from starting campfires or smoking in some areas to reduce the threat of sparking new wildfires, the National Park Service said Friday.

The famed Mariposa Grove, which includes more than 500 mature sequoias, has escaped serious damage but the area will remain closed to visitors. Ahearn said crews were cleaning up in the grove.

People who own private property as well as park employees who live in Wawona can return to their homes starting Sunday morning, but only with escorts. The area remains under a fire advisory.

Farther north, all evacuation orders and road closures were lifted Saturday morning in the Peter Fire in Shasta County. Crews also reported favorable overnight conditions and containment was at 65%, up from 34% Friday.

The California Department of Forestry and Fire Protection said the fire erupted shortly before 3 p.m. Thursday and destroyed 12 structures.