The gardens at the Hess Collection, one of this region’s better-known wineries, reeked of spilled cabernet on Monday. The wine barrel storage warehouses by the airport were a jumble of tumbled oak barrels. The wine library at Saintsbury — a room filled with old vintages — had the smell of a day-old party, a result of 500 bottles shattering on the floor.

The magnitude-6 earthquake that jolted this picturesque valley of wineries and vineyards early Sunday morning wreaked at least some havoc with the industry that has come to define this part of Northern California. “About 15,000 cases of lovely cabernet came pouring out those doors and down the steps, into the garden,” said Jim Caudill, director of hospitality at the Hess Collection winery in Napa.

But as winemakers and tourism officials began cleaning up and assessing the damage, there was evidence that the impact may not have been as widespread as suggested by the images that flooded Twitter and television screens.

As is often the case with earthquakes, the amount of shaking — and thus damage — can vary significantly within a few square miles. This was certainly true here in wine country, where there were drastically different, and sometimes conflicting, reports of damage from vineyard to vineyard on Monday. In many cases, wine had just been moved from oak or metal barrels, where the earthquake could cause the most spillage, to bottles stacked in cases protected by shrink-wrap.

Bruce Cohn, an owner of B. R. Cohn Winery, said he was at first disheartened when employees reported that his warehouse — which holds 5,000 barrels, some stacked six high — was in chaos, with wine spilled all over the floors. “I’ve been in this for 40 years, and I’ve never seen anything like this,” Mr. Cohn said, describing the tumbled bottles and spilled wine.

But as he reviewed the actual damage, he said, his worries began to diminish.

“My feeling is that it’s not that bad,” he said. “A lot of the barrels fell over, but I’m not sure they broke. I’m hoping — and I think — it looks a lot worse than it is, but we don’t know until we sift through it.”

At Saintsbury, a winery that makes about 30,000 cases a year, most of the damage was in and around a tin-roofed barn. Barrels stacked 16 feet high were knocked from a tight lattice into uneven piles that workers spent Sunday and Monday examining. Stainless steel tanks shifted a foot or more during the earthquake, but fortunately for the company, the tanks and barrels were empty: About a week ago, the company bottled and moved most of its inventory to Napa-area warehouses that were unaffected by the earthquake.

Richard Ward, Saintsbury’s 64-year-old co-founder, said the company has earthquake insurance, but, this being California, there is a $100,000 deductible, and he estimates the damage is in the $50,000 range. “We’ll just absorb it,” Mr. Ward said.

At Trefethen Family Vineyards, most of the wine survived the earthquake. The 2014 vintage was still on the vine, while earlier years had largely been moved out and stored elsewhere to make way for this year’s fruit.

“With the timing, we were very fortunate,” said Jon Ruel, president of Trefethen. Because the quake happened in the middle of the night, “we had no employees in any of the buildings,” he said, “and because of the time of year, we had less wine on site than we would at any other time.”

He continued: “The grapes are fine; they’re still ripening. And we had a lot empty barrels and tanks.”

But the visitor’s center, a wooden winery built in the 1880s, had buckled and was leaning 15 to 20 degrees to one side. “It was surreal,” said Janet Trefethen, whose family has owned the winery for half a century. “When you looked at it, it was like: ‘Is this real? Am I awake?’ “

Cate Conniff, communications director for Napa Valley Vintners, which represents 500 wineries, said her organization was in the early stages of assessing the losses.

“In the end, people who are growing grapes are farmers,” Ms. Conniff said. “This is a particularly strong expression of Mother Nature, but they deal with Mother Nature every day, and they are very resilient.”

In many ways, the earthquake could not have struck at a worse time for this valley, whose economic lifeblood is tourism and winemaking. This is the heart of the tourist season, as well as the middle of the harvesting season for a vintage that looks as if it might be a great one.

As the day went on, concern shifted from the damage to the vineyards to what the cascade of images of destruction would do to the tourism business. Beyond the actual wine, winemakers are worried about downtown Napa, which over the past two decades has been redeveloped from a run-down area whose main attribute was a multiplex theater across from a skateboard park to a more quaint mix of boutiques and ambitious restaurants.

Owners of the Buoncristiani Family Winery said they did not lose any wine, but as one of about 20 boutique wineries in the Vintner’s Collective — a building on Main Street in Napa that lost its facade in the earthquake — they lost their tasting room. “From the sales standpoint, it’s a little scary,” said Nate Buoncristiani, one of the four brothers who own the business. “I have no idea what’s going to happen.”

Clay Gregory, the president of Visit Napa Valley, the local tourism organization, said he was worried that visitors would stay away during what is normally the busiest time of the year.

“I’ve spent most of the day trying to get across to the world that the city is not on fire,” he said. “It’s not a catastrophe. It clearly was a very bad thing, and it impacted some wineries and some homes. But it’s not a catastrophe.”

He said that three blocks have been roped off, but that most of Napa is open and ready for business. (That said, among the offices that have been shut down because of earthquake damage was Visit Napa Valley.)

The loss to wineries includes equipment. The barrels cost as much as $1,500 each — a considerable sum, and potentially one of the more expensive legacies of the earthquake.

Mr. Buoncristiani spent part of Monday in a Napa warehouse used by multiple vintners, where his winery stores 200 empty barrels. Workers were using a crane to pull toppled barrels from the top of a precarious pile, one by one, a process that looked as if it could take weeks.

Mr. Buoncristiani, in shorts and flip-flops, tiptoed around purple sludge toward a pile of shattered barrels, looking for which ones were his. “There’s no way you can use this,” he said, pointing to a broken one. “Seeing this, I’m in shock.”

Ms. Trefethen, whose winery lost its visitor’s center, said she was confident the wine industry would survive. “We will go on,” she said, “and that building is going to get put back together.”