California fire crews make progress against ferocious Oak fire near Yosemite

Firefighters made progress against a ferocious wildfire in the foothills of the Sierra Nevada that forced thousands of residents from their homes in the gateway to Yosemite national park.

The Oak fire started on Friday near the town of Midpines, California, and exploded in size over the weekend.

But weather conditions improved on Sunday night, and by Monday morning, a heavily resourced firefighting effort achieved 10% containment.

Since Friday, the blaze has consumed more than 16,700 acres. More than 3,000 people were under evacuation orders.

More than 2,000 first responders from state and federal agencies were battling the blaze, attacking it both from the ground and the air. At least 10 homes and other structures had been destroyed, with thousands remaining at risk in its path.

The fire is one of dozens burning across the American west as the region braces for peak fire-risk months that still lie ahead. More than 5.5m acres have already burned in the US this year, roughly 70% more than the 10-year average.

California, a state that in recent years has faced intensifying threats from behemoth blazes, had seen a lighter-than-normal start to its highest-risk season. Spring rains offered a reprieve, delaying the onset of what officials still fear will be another devastating fire year. The Oak fire has showcased how quickly things can change.

On Sunday the California governor, Gavin Newsom, declared a state of emergency for the area, allowing for the deployment of thousands of emergency personnel.

The cause of the fire remains under investigation.

Firefighters working in steep terrain on the ground protected homes Sunday as air tankers dropped retardant on 50ft (15-meter) flames racing along ridgetops east of the tiny community of Jerseydale. Personnel faced tough conditions that included steep terrain, sweltering temperatures and low humidity, CalFire said.

Smoke drifted about 200 miles (322km) north toward Lake Tahoe and the same distance west into the San Francisco Bay Area, pollution control officials said.

In the chaos, a local man named Ron, who declined to share his last name, left behind his medication and his dog Duke, an ageing labrador mix with a bad hip.

The Associated Press contributed to this report