Tall grass from a deluge of winter rains is fueling wildfires throughout the Western U.S., damaging more than a dozen homes in Nevada and forcing residents from communities on the outskirts of Yosemite National Park in California, authorities said Tuesday.

Yosemite remains open to visitors, but flames threaten more than 300 homes and buildings in mountain communities southwest of the park, clearing out the small town of Mariposa.The Detwiler Fire has burned 25,000 acres and is 5 percent contained.

The fire burning since Sunday also puts at risk power lines providing electricity to the park, and it has closed roads traveled by tourists, officials said.

Gov. Jerry Brown on Tuesday declared an emergency, bolstering the state's resources to battle the fire that he said has forced thousands of residents to flee and is expected to continue burning.

Record rain and snowfall in the mountains this winter was celebrated for bringing California's five-year drought to its knees, but it has turned into a challenge for firefighters battling flames feeding on dense vegetation, officials said.

"There's ample fuel and steep terrain," said California Department of Forestry and Fire Protection spokeswoman DeeDee Garcia. "It makes firefighting difficult."

The area affected by the Detwiler Fire in Mariposa County.

Smoke from the fire in Mariposa County has drifted more than 150 miles away to Reno.

In a remote northeastern corner of Nevada, roughly 14 homes were damaged or destroyed by a wildfire that started Monday. Officials have lifted an evacuation advisory, allowing hundreds of people to return home and assess damage, authorities said.

In Nevada, wind is driving the flames through invasive cheat grass — growing twice the norm, U.S. Bureau of Land Management spokesman Greg Deimel said.

"It is very thick, very dense," he said. "You get the winds and the density of the grass, the fire just goes."

This summer's high temperatures follow a very wet winter that dumped more than 60 feet of snow at ski resorts in the Sierra west of Reno.

The California blaze near Lake McClure east of Modesto, has charred more than 45,724 acres and is only 7 percent contained. Officials report having it 7 percent contained.

It's burning near Highway 49, a historical route winding its way up California foothills of the western Sierra Nevada dotted with communities and landmarks that sprouted up during the state's Gold Rush.

To the south, crews have increased containment of a 29-square-mile (72-square-kilometer) blaze burning for a 10th day in the mountains of Santa Barbara County. It is 62 percent contained after destroying 16 homes.

Evacuation orders are in effect for the following areas:

  • 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.

Road Closures:

  • Hwy-49 at Hwy-132, restricted access to locals with addresses in La Grange, Coulterville, or Greely Hill only
  • Bear Valley Road at Exchequer Road
  • Hornitos Road and Old Toll Road
  • HWY-49 and Mt. Bullion Cutoff
  • Mt. Gains Road at No. 9 Road
  • Hwy 49 at Aqua Fria Road
  • Hwy 140 at Aqua Fria Road

An evacuation center has been established at Mariposa Elementary School, 7940 Mariposa Ave.

So far, one structure has been destroyed and one has been damaged.