The Sourdough wildfire has spread to approximately 38 acres, and Ross Lake Resort was evacuated Thursday, Aug. 3, according to the Southern Area Gray Incident Management Team. The power also went out at the resort, according to the management team.
The fire, caused by a lightning storm, has spread in part due to the “terrain-influenced rollout,” according to a Thursday update from the National Wildfire Coordinating Group.
“The fire is burning in some very steep, rough terrain,” said Pete Irvine, an information officer for the Southern Area Gray Incident Management Team — the firefighting team managing the fire. “Because of that very steep terrain, we are experiencing some downhill fire growth closer to the little community of Diablo, mostly due to rollout.”
Rollout, Irvine said, is material such as pine cones and branches that catch fire and roll downhill, spreading the fire farther south.
The fire is burning just a few miles north of Diablo Dam — operated by Seattle City Light — on the Upper Skagit River, and is at 0% containment. Even so, Irvine said the firefighting team, made up of 148 personnel and three helicopters, has had “good success” in preventing spread by dropping water with aircraft.
There are no evacuation orders in place for Diablo currently, though Irvine said the firefighters are working closely with Seattle City Light and the North Cascades Environmental Learning Center to protect the dam and other structures in the area.
In the meantime, the Washington State Department of Transportation has asked drivers not to pull over along state Route 20 near the Diablo Lake Dam. While the road remains open, they ask visitors to “keep in mind your safety and those of first responders and do not pull over to take photos or deploy drone aircraft,” the department tweeted Sunday.
Sourdough and Pierce Mountain camps are closed due to the fire, according to National Park Service. Access across Diablo Dam is limited to Skagit Tours, Ross Lake Resort and North Cascades Environmental Learning Center reservation holders only.
Campfires or the ignition of wood, briquettes, or any fuel in fire pits, fire pans, and barbecue grills is banned in all portions of North Cascades National Park. This includes all NPS lands and campgrounds along state Route 20, as well as Hozomeen and Stehekin Valley.
This story was updated at 5:53 p.m. Aug. 3, 2023, to include information about the evacuation of the Ross Lake Resort.