When Mary Ann McGuire landed in Napa Valley as a 20-year-old in 1960, she felt a special connection to the area.
“We saw it as a bountiful garden,” she says. “I felt this sense of power that came from the land…For me, it carried a spiritual imprint that a mother feels towards a child that you want to protect.”
For her first few years in the Valley, McGuire, who had moved to the region with her new husband, cattle rancher George Gamble, saw no reason to act on that protective instinct.
But in the mid-60s, California entered an era of development. And as more agricultural acreage gave way to subdivisions and shopping centers, the grape growers, farmers, ranchers and residents of Napa County began to feel the pressure of what that development might mean for the region.
For McGuire, that pressure first came to a head in 1965, when the United States Army Corps of Engineers stripped away the vegetation along the banks of Conn River, which ran straight through their ranch. It was replaced by a lining of concrete.
When McGuire learned the same concrete fate was destined for each regional waterway, she wouldn’t stand for it, and neither would her neighbors.
The community, connected by phone calls and door-to-door outreach, opposed the waterway project along with the development of a six-lane highway through Mt. St. Helena proposed by California Department of Transportation. Together, McGuire and others got both plans quashed.
Napa Valley’s residents back then saw a future of land covered in greenery and grapevines, but they also identified the fragility of that vision.
“We understood that maybe we got a freeway off [the] books, and the river thing defeated for the time,” says McGuire. “But nothing was going to stop the developers from coming up here.” They had seen it happen just miles away in Santa Clara Valley.
“In the mid-60s, Santa Clara Valley had pretty well been on its way to extinction as a place for grape growing,” says Warren Winiarski, famed Napa Valley winemaker and the founder and former proprietor of Stag’s Leap Wine Cellars.
In fact, Santa Clara Valley had more than 100,000 acres of orchards in 1940. That diminished to under 6,000 acres by 1990, according to Napa Valley Grapegrowers, a trade organization built to preserve and promote the region’s vineyards.
“The idea in Napa was to avoid that destiny and seek to preserve agriculture as a way of life,” says Winiarski.
So, community members brainstormed a way to keep Napa’s land for farming. “We thought, ‘How can we enact some legislation that will write that into law and then protect it? How can we preserve this wonderful valley for agriculture?’” says McGuire.
The answer was the Napa Valley Agricultural Preserve, a set of zoning laws enacted in 1968 to protect agricultural areas. The first legislation of its kind in the U.S., it declared that agricultural use was the best fate for Napa’s fertile foothills.
Initially, the Ag Preserve protected 23,000 acres of land, a number that has since increased to more than 38,000 acres.
Agriculture is the only commercial activity allowed on the protected lands. The Preserve also prohibits land being broken down to less than 40 acres, which prevents subdivisions and future development, according to Napa Valley Grapegrowers.
“I have nothing against subdivisions, but houses you can have anyplace,” says Winiarski. “There’s only a few places with potential for the great beauty in the fruit and the wine that’s made here.”
The whole community needed to get on board with the project. A committee was formed, chaired by Jack Davies, winemaker of Schramsberg at the time. Everyone had a role to play.
For Winiarski, a Napa newcomer at the time, that meant going door-to-door in the area he lived, Angwin, to advocate for the preserve.
“Since I lived up there, I was given the responsibility of getting that community, Pacific Union College, and the president of the college [to support the movement],” he says.
But not everyone backed it. Unlike the highway and waterway issues, which McGuire says unified many across the valley, the Ag Preserve saw some backlash.
“There was much local consternation,” says Ren Harris, founder of Napa Valley Grapegrowers and past president and owner of Paradigm Winery. “You know, those who didn’t like people telling them what they can do with their land.”
Harris was an avid supporter of the initiative and attended every hearing held by the Planning Commission and Board of Supervisors.
Ultimately, it passed both boards unanimously, he says.
But even in success, the growers saw the need to strengthen the protection to prevent it from being chipped away over time or challenged by future governments.
At the Ag Preserve’s inception, Napa Valley wasn’t the internationally respected wine region it is today.
When the Ag Preserve was implemented in 1968, Napa Valley had 14,000 acres of vineyards. By 1975, that swelled to 24,000 acres.
That next year brought the now-legendary “Judgment of Paris,” where Stag’s Leap Wine Cellars’ 1973 Cabernet Sauvignon, crafted by Winiarski, and a 1973 Chardonnay from Chateau Montelena won first place. It was a first for California, and it exemplified the quality of wine that Napa Valley could produce. Since the Ag Preserve’s inception, not a single acre of protected agricultural land has been converted to urban use, according to the Napa Valley Grapegrowers.
In Napa, the preservation mindset seems to have been passed down like much of the land itself. The next generation of Napa Valley growers, like Tom Gamble, an Oakville-based vintner, McGuire’s son, have taken the mantle.
In 1990, the younger generation pushed through an ordinance known as Measure J, which required a referendum to convert protected agricultural land to nonagricultural use, rather than by a vote by the Board of Supervisors. This move was expanded in 2008 by Measure P, which significantly strengthened the integrity of the Ag Preserve until at least 2058.
“This love of the land, my mom and my dad and my other forebears passed that on to us and really led by example,” says Gamble. “So, I think that’s why you still have the Farm Bureau and the vintners and other organizations wanting to work so hard to preserve this place.”
Gamble, who counts sustainability as a core value of his Gamble Family Vineyards, learned by the example of his parents and their peers not to take Napa Valley for granted.
“People think it just happened or it’s always been like this, and it hasn’t,” he says. “It was a fight. It’s a fight to this day.”
The consensus among Napa Valley’s grape growers is that without the Ag Preserve, the region’s fertile land would be paved over and populated.
“I firmly believe that without the Ag Preserve, Napa Valley would probably not be much of a factor in the world of wine today,” says Harris.
“We have to think about things that support that preservation, which means looking forward, anticipating problems, taking account of limitations and acting in a way to continue making the beautiful wines that we have in the past,” says Winiarski. “I feel to the extent that I’m able, I should continue to make whatever contribution I can to that same cause that I worked for in the beginning, to avoid things that would diminish the valley’s ability to go on into the future.”
Last Updated: May 8, 2023