World

California wildfire prompts Yosemite travel restrictions

Firefighters determined to keep a massive blaze from raging into the heart of California's Yosemite National Park have shut down half of its main east-west corridor, just days before a holiday weekend marking the end of the peak summer tourist season.

Blaze scorches over 776 square km of forest land

More than 4,500 firefighters are battling the blaze, backed by teams of bulldozers, water-dropping helicopters and airplane tankers carrying payloads of flame-retardant chemicals. . (Max Whittaker/Reuters)

Firefighters determined to keep a massive blaze from raging into the heart of California's Yosemite National Park have shut down half of its main east-west corridor, just days before a holiday weekend marking the end of the peak summer tourist season.

A long stretch of Tioga Road through the western half of the park was closed on Wednesday as fire crews tightened their grip on the blaze, extending containment lines around 30 per cent of the wildfire's perimeter by the end of its 12th day.

[IMAGEGALLERY galleryid=4928 size=small]

The so-called Rim Fire has blackened about 77,902 hectares, or more than 776 square kilometres, of dry scrub and timberlands, mostly in the Stanislaus National Forest west of the park. Its cause is still being investigated.

The firefighting force of more than 4,500 is backed by teams of bulldozers, water-dropping helicopters and airplane tankers carrying payloads of flame-retardant chemicals.

The battle inside Yosemite is focused largely on preventing flames from advancing any farther toward the core of the park, famed for its towering rock formations, waterfalls, meadows and pine forests.

Some four million people visit Yosemite each year, most of them during the peak months of June through August. Park officials said they have already noticed a decline in the crowds of visitors typically seen in late summer.

Blaze bigger than Chicago

With an overall footprint that exceeds the land mass of Chicago, the blaze ranks as the sixth-largest California wildfire on record.

As of Wednesday less than a quarter of the total burned landscape, about 43,000 acres, lay inside Yosemite, confined to the northwest corner of the 300,000-hectare park.

Earlier this week, flames closed in on the park's Hetch Hetchy Reservoir, which supplies 85 per cent of the water consumed by San Francisco and several other communities some 320 kilometres to the west.

But utility officials said there was little risk to the artificial lake because of the rocky terrain and lack of brush surrounding it.

On the opposite end of the sprawling fire zone west of Yosemite, crews fought to keep flames away from some 4,500 homes in a string of small communities along the fringe of the Stanislaus National Forest, said California Department of Forestry and Fire Protection spokesman Dennis Matheson.

Most of those dwellings have been ordered evacuated or were under advisories urging residents to leave voluntarily or be ready to flee at a moment's notice.

The fire has already destroyed dozens of homes and cabins, but no serious injuries have been reported.