The Detwiler Fire on Thursday was threatening about 1,500 homes and other buildings, after already destroying 45 structures. It's not clear what type of buildings burned.
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The flames are near Highway 49, a historical route winding through Sierra Nevada foothills dotted with little towns that drew gold miners to California in the 1800s.
More than 3,000 firefighters are battling the 5-day-old blaze that has scorched 109 square miles, the California Department of Forestry and Fire Protection said.
The fire has forced almost 5,000 people from homes in and around a half-dozen small communities, officials said.
Heavy smoke hung in the air over Mariposa, a town of 2,000 people with century-old wooden buildings, including what's touted as the oldest active courthouse west of the Rocky Mountains.
The fire got within a half-mile of Mariposa, but crews have been able to keep it out of the town, fire spokesman Jason Motta said.
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"Most of the town of Mariposa has not been affected by anything other than the smoke," Motta said.
At its closest, the blaze was still about 35 miles from the boundary of Yosemite, where campgrounds are open, park spokesman Scott Gediman said.
The fire closed one of several roads into the park during its busy summer season, and rangers warned visitors with respiratory problems to be mindful of the smoky haze over the park's landmark Half Dome rock face, Gediman said.
Yosemite does not appear at risk from the fire, which was moving south, away from the park, fire spokesman Jordan Motta said.
Tony Munoz, 63, and his wife, Edna Munoz, 59, were ordered out of their home outside Mariposa on Tuesday. They grabbed clothes, medicine and their three dogs and a cat before fleeing.
Driving out on narrow, congested roads, "you couldn't even see the sun" in the ash-filled sky, said Tony Munoz, a school custodian.
Downtown Mariposa was empty except for firefighters and other emergency workers. Fierce flames were visible on slopes about a mile away.
Record rain and snowfall in the mountains this winter abruptly ended California's five-year drought. But that has increased the challenge for crews battling flames feeding on dense vegetation.
"There's ample fuel and steep terrain," Cal Fire spokeswoman DeeDee Garcia said. "It makes firefighting difficult."
Statewide, about 6,000 firefighters were battling 17 wildfires, including about 2,200 at the fire near Yosemite.
Gov. Jerry Brown has declared an emergency, bolstering the state's resources to battle the fire.
ABC7 News contributed to this story.
DETWILER FIRE INFORMATION
Acres burned: 70, 096 acres
Containment: 10 percent
Structures Threatened: 1,500
Structures Destroyed: 45 destroyed and 6 damaged
Evacuation orders are in place for:
- City of Mariposa, Mount Bullion Ridge Road from HWY 49N to CYA Road
- Old Toll Road between Corbett Creek Road and HWY 49N, including Corbert Creek Road.
- Mount Gains Road to No.9 Road including No.9 Road
- Mount Bullion Cut off Road and Agua Fria Road from HWY 49N to HWY 140
- HWY 49N to Baxby Bridge to Agua Fria Road; Area known as Mount Bullion
- HWY 49N from Mount Bullion Ridge Road to Old Toll Road
- Pendola Garden Road from HWY 49N to Old Toll Road (Exit via Old Toll Road only)
Evacuation Advisories are in effect for the following areas: All of CYA Road.
Red Cross Evacuation Shelter:
EV Free Church
50443 School House Road
Fire Information Line: (844) 668-3473
HWY-49 at HWY-132 (Coulterville Rd.) - Restricted access to locals with addresses in La Grange, Coulterville, or Greely Hill only
Bear Valley Rd. at Exchequer Rd.; Hornitos Rd. and Old Toll Rd.; HWY-49 and Mt Bullion Cutoff.; Mt. Gains Rd. at No.9 Rd.; Hwy 49 at Aqua Fria.; Hwy 140 at Aqua Fria.
The communities of Hunters Valley, Bear Valley, and Hornitos continue to be threatened as the fire encroaches on culturally and historically sensitive areas.
Traffic along HWY 41 & 49 will be impacted as a result of road closures on HWY 49. The fire continues to threaten power lines to the south of the incident, which supply power to Yosemite National Park.
Firefighters on the ground as well as aircraft are actively working to contain and suppress the fire. CAL FIRE Incident Management Team 4 assumed command of the incident at 1000 hrs. from the Madera, Mariposa, Merced Unit.
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