A fast-moving wildfire charged through inaccessible terrain and climbed out of a steep canyon along the middle fork of the American River Wednesday as people living in the area sought safer ground.

Firefighters braved triple-digit temperatures to battle the blaze in a rural subdivision 50 miles northeast of Sacramento. Placer County sheriff's spokeswoman Dena Erwin says homes near Todd Valley between the cities of Foresthill and Auburn were evacuated as the fire quickly grew to roughly 300 acres.

California Department of Forestry and Fire Protection spokesman Daniel Berlant tells Sacramento station KCRA-TV that the evacuations were called because the community only has one way in and one way out.

"It's all hands on deck... we have everyone up there working on evacuations," she said.

The fire began Tuesday afternoon in El Dorado County before jumping the river and climbing out of the canyon and into neighboring Placer County.

Firefighters on the ground and in the air were working in 101-degree heat against the fire in a remote, rugged area that is difficult to access, said California Department of Forestry and Fire Protection spokeswoman Lynnette Round.

"It's in some really steep terrain. We have air and ground units out there working really, really aggressively to put this fire out," Round said.

KCRA-TV reported a drone spotted over a section of the fire grounded aircraft in the area for about an hour as the Placer County Sheriff's Office worked to find the owner. Air attacks resumed Tuesday evening with a D-10 Airtanker making drops over the flames.

The Associated Press contributed to this report.