Los Angeles, Aug. 6 -- Hundreds of structures are threatened by a fast-moving wildfire that has scorched over 82,000 acres (about 332 square km) in less than five days in Central California, authorities said Tuesday.

The wildfire, dubbed the Gifford Fire, broke out Friday afternoon when four separate ignitions along a California highway merged into a single wildfire currently burning on the Santa Lucia Road in both San Luis Obispo and Santa Barbara counties, according to the U.S. Forest Service and the California Department of Forestry and Fire Protection.

Authorities said that the blaze is threatening more than 870 structures and was only 7 percent contained as of Tuesday morning.

The fire has prompted evacuation orders for residents...