By Esther Mobley

San Francisco Chronicle

SAN FRANCISCO – As massive fires burned through Napa and Sonoma counties, the heart of the American wine industry, winery owners scrambled to determine the extent of the damage to vineyards, their homes and their businesses.

Of the hundreds of wineries in the region, nearly all were forced to close on Monday, and a handful of wineries were burned to the ground, such as Signorello Estate in Napa and Paradise Ridge in Santa Rosa. Others including Continuum Estate on Napa's Pritchard Hill and Cliff Lede Vineyards in Yountville remained untouched, but vigilantly watched, as fires surged closer.

Meanwhile, the entire industry is bracing to confront the long-term consequences of an unprecedented natural disaster that could affect the supply of grapes, the quality of the region's wines and the local tourism industries for years to come.

The industry also prepared to grapple with the loss of historic properties. White Rock Vineyards, whose Soda Canyon area winery was first established in 1870, was completely gone, said a staff member. And some historic vineyards, especially in Sonoma Valley -- irreplaceable old vines dating back to the 19th century, in some cases -- were feared singed.

Joe Nielsen drove over to Donelan Family Wines, where he is the winemaker, around 7:30 a.m. Monday. He saw the industrial park at Coffey Lane in flames, blocked off by fire trucks. By 10 a.m., it was clear that his winery had been spared, though homes just across the street were singed.

``It looks like a bombing run,'' said Nielsen, who had evacuated his own home in Santa Rosa around 2 a.m. ``Just chimneys and burnt-out cars and cooked trees.''

When he entered the winery, he found it full of smoke, and sealed all of his tanks – still full of fermenting grape juice – in the hope that carbon dioxide might push out any smoke that might taint the nascent wines.

Even though the fate of the wines looks bleak, Donelan was luckier than many wineries, in that its building did not burn.

Other areas were not so fortunate. Atlas Peak and its surroundings in Napa Valley were particularly hard-hit. Signorello Estate, on Silverado Trail, was completely destroyed; buildings at nearby Stag's Leap Winery burned, too. California Highway Patrol airlifted about 30 workers off of Atlas Peak late Sunday night, where roads had become impassable, according to David Shew, a spokesman for the California Department of Forestry and Fire Protection.

On Monday evening, roads connecting to Atlas Peak remained closed, and many vineyard owners still had no idea what had happened to their properties.

Meanwhile, fires burning around Sonoma Valley appeared to have consumed Nicholson Ranch, a winery just off Sonoma's Highway 12. Jake Terrell, vineyard manager for St. Francis Winery, said its Behler Vineyard had fires burning on all three sides, but was itself safe. At Sonoma Valley's Scribe Winery, Cal Fire was successfully holding off nearby flames, said owner Andrew Mariani.

Santa Rosa was another hot spot, extending from areas downtown -- where there are many industrial wineries, like Donelan – through the Mark West Springs area, toward Calistoga. But many vintners had evacuated the area and had not yet returned to survey the damage.

In Napa and Sonoma counties, autumn is the busiest time of year for the region's hospitality industries, when harvest is under way. Most wineries are close to completing this year's harvest, and most of the grapes are in tanks or barrels.

The Napa Valley wine industry, which employs 46,000 people in the county, last year saw 3.5 million visitors, generating $80.3 million in tax revenues, according to research firm Destination Analysts. In Sonoma County, according to the county tourism board, annual tourism spending is around $1.93 billion.

However, the immediate concern is for the thousands of people working in vineyards at this time of year.

``We were set to pick at Moon Mountain vineyard, and instead spent it chainsawing some trees out of driveways for friends,'' said Eppie Ordaz of Ordaz Family Wines, based in Kenwood. ``Pretty much the entire eastern mountain range from Santa Rosa to Glen Ellen looked like it was burning.''

In Santa Rosa's Bennett Valley, a night pick was already in progress at Carlisle Winery when evacuation orders came through. The workers harvested grapes in smoke until around 5 a.m.

``They got it mostly picked, and then had to evacuate,'' said Carlisle owner Mike Officer.

Hall Winery is one of the many businesses with a vineyard on Atlas Peak. Like others, Hall is still wondering about potential impacts, according to Jamie Chandler, the director of marketing for Hall Winery. Similarly, Tegan Passalacqua of Turley Wine Cellars had been told that Mead Ranch, also on Atlas Peak, has burned, but is still awaiting confirmation.

Benovia winemaker Mike Sullivan said the Santa Rosa winery was fine -- but his home, near Santa Rosa's Wikiup area, was not.

``I am sure my home is gone,'' he said. He evacuated to the winery just after 1 a.m. Monday, where there is a generator.

Dan Kosta, founder of Kosta Browne Winery in Sebastopol, had evacuated with his three children around midnight from their home off Mark West Springs Road in Santa Rosa.

``That whole area is just gone,'' he said. ``It was getting to be too windy and smoky there, and there were ashes -- you couldn't breathe when we left.'' Kosta and his children first went to John Ash & Co., the restaurant where he once worked, but when the fire began approaching there, too, they drove north to Healdsburg.

In terms of long-term effects surrounding major fires, the usual winemaker concern is smoke taint – whereby lingering ambient smoke can imbue grapes with a strong flavor and permanently impart itself into the wine. But vineyards burning entirely to the ground – that is far more perilous altogether.

Depending on how widespread the destruction of vines is across Wine Country, it could mark a severe shortage of grapes for years to come. When vineyards are planted, it can take 3 to 5 years for them to bear fruit. Additionally, most Napa and Sonoma wineries hold at least three vintages of wine in barrel at any given time, not to mention the large inventory of bottles that many wineries hold back for years.

Elsewhere in the hospitality industry, the historic Fountaingrove Inn in Santa Rosa confirmed on Facebook that guests were evacuated and the hotel was destroyed.

Willi's Wine Bar, a critically acclaimed restaurant at 4404 Old Redwood Highway, burned down early Monday as well. Owner Terri Stark confirmed the news.

``Everyone was gone except one of the managers, who tried to hose it down and turn the gas off,'' Stark said. ``But eventually he had to leave.''