By The Associated Press July 24 2015 06:00 AM EDT weather.com

Residents of about 50 of the 200 homes evacuated from of a wildfire burning near Northern California's Napa Valley wine country were allowed to return home Thursday night.

"The threat has diminished pretty substantially in a lot of areas," said Amy Head, state fire spokeswoman. "We didn't have a lot of growth today (Thursday), which is good."

Chris Dolce, meteorologist for weather.com, said calmer winds help contain the blaze. Temperatures hovered near 75 degrees.

"Strong winds are not expected the next couple days in the area of the Wragg fire," Dolce said. "However, given the terrain where this fire is located, winds could be erratic at times."

<img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/ChrisZ_Vacaville_650.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/ChrisZ_Vacaville_650.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/ChrisZ_Vacaville_650.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > The Wragg Fire in Napa County, California, as seen from Vacaville. (Chris Zumwalde/Instagram) (Chris Zumwalde/Instagram)

Since it started Wednesday, the blaze has burned 10 1/2 square miles in drought-parched countryside near Lake Berryessa, about a 45-minute drive from Napa Valley.



The most active part of the fire is burning along a mountain range in a remote area several miles from the highway that feeds into the lake park.

The blaze is burning in a remote area, several miles from a highway that feeds into Lake Berryessa. Fire crews are scooping water from the lake, dumping it onto flames burning along mountain tops.

(MORE: Glacier National Park Wildfire Grows to 4,000 Acres, Prompts Multiple Evacuations; Road Closed )

The fire was 30 percent contained by Friday night, but 140 homes and ranches were still threatened. A few hundred people left their homes and most went to stay with friends and family.

The Canyon Creek and Lake Solano campgrounds were also evacuated.

The fire erupted Wednesday afternoon and was initially reported as being caused by a vehicle accident, but authorities said Thursday that the cause was still under investigation.

More than 520 firefighters are battling the flames in rugged, steep, brush-covered terrain that has been difficult to access.

Lake Berryessa is one of the largest bodies of fresh water in California and a short drive east of California's famed Napa Valley wine country, though the wineries remain safe.

"It's pretty far away from the Napa Valley," Head said, adding that people are "fine to go into the Napa Valley and do tastings."

State Route 128 remains closed at Wragg Canyon.

Marcia Ritz, owner of the Spanish Flat Country and Deli in Napa, said she was forced to turn around from a shopping trip when the flames broke out. A commute that's normally 45 minutes took more than three hours.

"There were huge amounts of smoke," said Ritz, whose store was not in the evacuation zone.

She worried about the impact the fire would have on tourism.

"We have the resorts up here, and in the summertime we depend on them," Ritz said.

<img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/smoke-izzysdaddy7-instagram.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/smoke-izzysdaddy7-instagram.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/smoke-izzysdaddy7-instagram.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > Smoke in the sky near Winters, California, Wednesday evening. (izzysdaddy7/Instagram)

<img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/smoke-plume-radar.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/smoke-plume-radar.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/smoke-plume-radar.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > Radar image from late Wednesday showing the smoke plume over Winters, California.

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