At 3:20 a.m. on August 24, 2014, the ground in Napa, California started shaking, heralding a 6.0 magnitude earthquake. It was the region's largest seismic activity since 1989's Loma Prieta quake, and although it only lasted about 10 to 20 seconds, varying by location, that was more than enough time for the temblor to tear buildings apart, spark fires, and send hundreds to area hospitals with injuries. It also caused millions of dollars worth of damage to homes, businesses and infrastructure, and especially the region's famous wineries.

One of the hardest hit wineries was Trefethen Family Vineyards, an operation known throughout the valley for its unique wooden production building dating from 1886. I spoke with Hailey Trefethen, a third-generation vintner who works with her family’s winemaking and viticulture operations, about the damage sustained to Trefethen’s iconic National Register-listed building and the rehabilitation efforts than are underway.

Now propped up on steel buttresses, the building is estimated to take about one to two years to restore, and the total cost of the overhaul is not yet known. The Trefethen family, however, hasn’t let the damage to its beloved building crush its spirits.

Can you tell me a little bit about the building’s history?

The winery itself was built in 1886 by Hamden McIntyre, a pretty well-known architect of wineries at the time. He did what we call the “Big Four” in Napa. Our building was [originally called] Eschol, and then he built Inglenook and what is now the Culinary Institute of America at Greystone. All of those buildings are similar in design and gravity flow.

What’s really unique about the Eschol/Trefethen building, our building, is that it’s all wood. All the others were stone.  The others are all set up against a hill so that horses could bring grapes around to the back. Here, they had to develop an elevator system to get the grapes up to the third floor -- they had a horse-drawn elevator that did that.

There aren’t a lot of wooden buildings from that time, especially no wooden wineries from that time, that still exist. It’s really pretty unique in that sense. It’s all cut-and-groove redwood on the inside, and I can’t stress enough how amazing it is -- so warm and homey, and you know it’s been there for a long time.

The winery building awaiting restoration.

The building has three uses: barrel storage, our tasting room and offices. We’re sharing offices [in some of our other buildings] and we have a little bit less room now. The tasting room is set up in a tent, but once you get inside you have an 180-degree view of our vineyard and it's pretty wonderful.

One of the really interesting things for people to know is that in Napa in the 1880s, there were over 140 wineries. It’s always had this great agricultural history. It’s great that you still have wineries from that era that survived Prohibition, phylloxera, and two world wars. My grandparents bought the winery in 1968; the vineyard was run down, and they planted trees wherever there was room.

Can you detail a little bit of the damage that was sustained by the wooden building?

The building was leaning four feet to the west [after the earthquake], and it was the first floor that was really leaning over. The second and third floors aren't perfectly straight, but they are barely still kind of in line and plumb. They definitely move together.

That building, I think if it was stone, would not have been able to sustain this earthquake. We’re just incredibly lucky that wood is a little bit more flexible and can take that. It really is this building's architecture and how it’s put together that kept it standing.

Although Trefethen’s main building suffered damage, the vineyards were largely unharmed.

How did the earthquake affect your day-to-day operations? 

The earthquake affected us in the sense that we’re now sharing offices and things like that, and that our tasting room is currently only in a tent. But, the other part of it I guess would be barrel storage and winemaking in general. Our crush pad sits almost right in front of that building, so we had to make some changes to our crush operation, but we were able to do that and bring fruit in later that week, which was hugely important to us because it was right at the beginning of harvest.

As I mentioned, we’re an all-estate winery, so everything happens here. We grow every single grape, we crush every single grape, everything goes through fermentation and is bottled on-site, and it doesn’t leave until it leaves with a customer.

Where are you with the building restoration, and what still needs to be done?

We’re working with historical architects, and they’ve helped us develop our preservation plan, which will guide the entire process. It will allow us to use as much original material as we can.

We look at it kind of in two stages -- the first one that we’re really focused on right now is getting the building plumbed in and getting it straightened. We’re going to have to see how the building reacts. We’re going to put in more supports, and will have hydraulic jacks; we’re working on pushing the building back an inch a day. We can’t do anything fast-paced.

Once the building is upright, we’ll begin a little more of the restoration. We’re working with the structural engineers to look at the best way to do an earthquake retrofit that is in line with its history and the time it was built, and the best methods that are in line with keeping its historical integrity.

Who are you working with?

Our structural engineer is ZFA, who has done a lot of work in Napa with other structural buildings. We have a lot of confidence in their ability to work with historic buildings and understand the historic building code. Stacey De Shazo [of Napa County Landmarks] is helping us, and our architect as we move forward is Maurice Lombardo of Taylor Lombardo Architects.

It’s been a real treat to have historic architects on the property, and they’ve helped remind us how much we love this building and how special it is. People across the country who have visited us have shown an outpouring of support, and reminded us that it is a really cool building that should be preserved. We’re excited to be able to continue to share that.

BONUS: Skip to the 5-minute mark in this video for an on-camera interview with Hailey Trefethen.