While scores of Napa Valley wineries sustained some degree of damage in last weekend’s earthquake, 95 percent of the valley’s wineries are open for business, a local trade group said Wednesday as it urged visitors to return to Wine Country with the harvest season underway across the North Coast.

The extent of the damage to the wine industry from the magnitude-6.0 earthquake that struck near American Canyon on Sunday still is being tallied, said Linda Reiff, executive director of Napa Valley Vintners. Many wineries are still conducting inventory on how much wine they lost.

“There are still some people who are just getting into their buildings, so we don’t have a good estimate,” Reiff said.

The earthquake struck a small but lucrative and highly visible piece of California’s wine industry. Though its vineyards produce less than 4 percent of the state’s wine grapes, Napa County growers took in nearly 20 percent of the $3.3 billion spent on California wine grapes last year. The impact of the quake on the county’s wine industry — and its ability to process the $650 million grape crop now ready to be harvested — has drawn intense interest from around the globe.

About 20 percent of the trade group’s 500 members experienced some damage, said Russ Weis, chairman of Napa Valley Vintners. The most serious damage primarily was centered on the Carneros region, but the temblor also caused problems in other pockets.

For example, Weis noted, the Laird Family Estate Winery off Highway 29 in Napa suffered some extensive damage, which was an immediate concern for some local wineries because it serves as a custom-crush operator for a number of clients.

As they clean up damage, wineries also face additional hurdles in tracking the inventory, as they must also report losses to the federal Alcohol Tobacco Tax and Trade Bureau, or TTB, and the state Department of Alcoholic Beverage Control, he said.

The agencies have been helpful, Weis said. The TTB said earlier this week it will consider waiving late filing, payment or deposit penalties on an individual basis because of the quake.

The trade group held a press conference at the banks of the Napa River to also urge people to visit the area, fighting back against the perception that the region was a large disaster zone to be avoided, spurred by photos on social media and some initial news accounts.

“It’s a big concern. It’s a lesson that a lot of folks have learned who have been in natural disasters,” Weis said. “We really need customers. The last thing folks need while they try and recover from their personal loss is not to have a job to go to.”

The trade group also set up an online forum where wineries that suffered little or no damage can offer assistance to those who are tallying big losses.

For example, Burgess Cellars has offered help as it has a spare 10,000-square-foot facility in its Triere vineyard in the Oak Knoll District. The winery primarily uses the facility for bottling.

“I’ve got barrel racks that are 70 percent empty . . .  I have a press and electricity,” winemaker Steve Burgess said. “It would be really easy to help someone out.”

The winery has not had anyone accept the offer, but Burgess said he has heard from one winemaker who may need to store 300 barrels. Burgess Winery did not suffer any damage, he said, as the winery’s main production facility was a solid metal structure built in 2000.

On Wednesday, the Napa Valley Vintners established a $10 million relief fund to assist the community as it rebuilds from Sunday’s earthquake. It will partner with the Napa Valley Community Foundation in administering the fund.

The group set up the fund in an effort to provide immediate financial support for individuals and businesses that suffered damage from the temblor. It will also serve as a repository for earthquake- related donations and to augment any government support.

More information can be found on the group’s website.

You can reach Staff Writer Bill Swindell at 521-5223 or bill.swindell@pressdemocrat.com. On Twitter @BillSwindell.