< All Blog Posts

Templeton Gap District

August 4, 2021

The Paso Robles American Viticultural Area (AVA) was established in 1983 and at that time there were 556,765 total acres with a little over 5,000 under vine. In 1996, the AVA expanded by 52,600 acres and then again by 2,635 acres in 2008. In 2007, a petition was sent to the federal government to establish 11 districts within the Paso Robles AVA. In the same year, a conjunctive labeling law (AB 87) was passed, which preserves the brand awareness of the Paso Robles AVA by ensuring that “Paso Robles” will always be seen in conjunction with the districts on wine labels. These 11 districts within the Paso Robles AVA were finally approved in 2014.

The Paso Robles Wine Country Alliance is continuing to focus on all 11 AVAs in this blog through 2021, in alpha order.


The story of the Templeton Gap district is well-rooted in viticulture. It is one of the oldest planted regions in California and only recently owes its name to the wine industry. Grape growing in the region began in 1856 when a Frenchman named Adolph Siot planted the first vineyard along a road now known as Vineyard Drive. He established a commercial winery adjacent to the vineyard in 1890 and was the only commercial winemaker until 1917. The Rotta family purchased Siot’s vineyard and winery in 1908 and renamed it Rotta Winery. Nearby, the Pesenti family planted grapes in 1923 and established its namesake winery in 1934. Both wineries gained local reputations for fine, affordable Zinfandels. In 1924, Sylvester Dusi planted Zinfandel at Dusi Ranch, located three miles south of Paso Robles and east of Highway 101. The Dusi family farmed and sold Zinfandel grapes for more than 80 years, only to establish a winery three generations later.

An expansion of grape growing and winemaking in the region began in 1976 when Pasquale Mastan started Mastantuono Winery near the corner of Highway 46 West and Vineyard Road. Where Donati Family is today. Ken Volk established a vineyard and eventual winery along Templeton Road, southeast of Templeton in 1982, Wild Horse Winery and Vineyard. Fratelli Perata was established in 1989 during a time when the region was still counting the order of wineries established following the creation of the Paso Robles AVA in 1983, making them number 12. Hope Family Wines / Austin Hope Winery, then called Hope Farms Winery, was established in 1990 right along Highway 46. The expansion would continue along this stretch of highway within the Templeton Gap as it was seen as prime land not only for growing grapes but for the eventual tourism trade that could easily access wineries along this busy thoroughfare.


The name Templeton Gap is of recent origin, and it is a name that originated in the wine industry. It is widely accepted that Ken Volk coined the name “Templeton Gap” in 1982 when he began planting a vineyard east of the town as he used it to describe the route by which cool afternoon winds flowed inland from the Pacific Ocean through passes in the Santa Lucia range during summer and early fall. He noted that it helped to moderate temperatures in vineyards, including his own, around the Templeton area, as well as areas south and west of Paso Robles. To break it down further, the name combines “Templeton,” the town in the region founded in 1886, and “gap,” defined in the dictionary as “mountain pass” or “ravine”. The first time Templeton Gap appeared in writing was on Wild Horse Winery and Vineyards’ marketing and public relations material. Eventually, references of the Templeton Gap would appear in The Wine Atlas of California and the Pacific Northwest by Bob Thompson in 1993, in a Sunset Magazine article “California’s Heritage Wine,” by Lora J. Finnegan in 1995, as well as The Wines of California by Stephen Brook in 1999.

To establish some clarity, after the term Templeton Gap was coined, it was used in two parts. One, to describe the specific climactic effect happening of cool ocean-borne breezes funneling through the Santa Lucia range into the Paso Robles AVA. Two, it has become the geographic name by which many wineries and vineyards use to refer to the region that they are in. It was only after 2014, when the 11 districts within the greater Paso Robles AVA were formerly established, that the name Templeton Gap became official for that geographic area.


The Pacific Ocean is approximately 18 nautical miles to Paso Robles from its closest point being the town of Cayucos, which sits at the inner apex of Estero Bay. The western border of the Templeton Gap district is much closer and as the marine layer builds across Estero Bay to altitudes of 1,400–1,800 feet, the heavier marine air spills across the range crest, easily depicted by large fingers of fog reaching over the mountains like a massive fog monster. This cool air spills through the gap along the Highway 46 West corridor and continues to flow to the lower elevations to the east, across the Templeton Gap viticultural area, and into the El Pomar District, Creston District, and the Paso Robles Estrella District. The warm days of Paso Robles have a direct cause and effect on this cooling influence. As the temperature gradient rises a vacuum effect pulls the spilling cool air inland and like clockwork, by 3 p.m. the cool breeze begins.

Although cooling breezes can find their way inland up and down the coastal range, it is the aligning of factors that create the very specific Templeton Gap effect that helps to not only cool off the Templeton Gap District but many other parts of the greater Paso Robles AVA. There is a slight overall topographic elevation drop that aligns with Estero Bay, as well as east to west ravines that are conducive to channeling airflow. Although Estero Bay does not have a submarine canyon, water remains cold year-round, adding to the climatic uniqueness of the region through advection fog, which is the combination of a cool surface mixing with warm moist air.

Because of this accelerated airflow through the gap, the Templeton Gap District is windier than much of the rest of the Paso Robles AVA. It also sits up against the mountain range and extends to the east with lower elevations, well within the rain shadow of the mountains. This results in an approximate average of 20 inches of rain per year.

Many of the vineyards are planted on south-facing slopes, effectively facing into the maritime air as it flows from the gap. The cool climate increases the ripening period for grapes, resulting in longer hang-time with later harvest dates of up to two weeks. This cooler area is conducive to wine grape varietals that excel in cool climates, including Pinot Noir and Chardonnay. The natural vegetation reflects the climate of the area well, with mixed woodlands over most of the area, transitioning to more open oak woodlands at the lowest elevations where it is slightly drier.

Soils and Terrior

The Templeton Gap District is considered one of the coolest of the Paso Robles AVAs. It is a region type II according to the Amerine and Winkler scales, which in essence puts it at about an average of 2,900 growing degree days. This is equivalent to other growing regions like the Duoro Valley, Piedmont, and Bordeaux, which are also in the 2,900 range.

The geology of the Templeton Gap District is essentially a result of uplift from the Santa Lucia Range west of the Rinconada fault as well as a lot of erosion of the soft Monterey formation marine shales, mudstones, siltstones, and sandstones. The eastern slope of the Santa Lucia Range dramatically rises from the Salinas River, forming the western and northern boundaries of the district. As you travel east in the district, the Salinas River and various creeks have down cut into channels and floodplains, resulting in the exposure of higher alluvial terraces and fans set above the river channels. Sloping hills and cuestas frame the district to the south.

Soils are mostly the Linne-Calodo complex of alkaline clay loams on hillsides and river terraces. On the steepest slopes, you will find the Gaviota-rock gravelly loam and most of the terraces have the Lockwood-Concepion complex of shaly loams. Although some of the soils have slightly acidic topsoils with pH values of 6.1 to 6.8, others are neutral to slightly alkaline even at the surface with pH values of 7.0 to 7.8. As a result, natural acidity abounds in much of what is grown in this region.

The District

The terroir of the Templeton Gap District possesses some ideal conditions for the cultivation of excellent wine grapes, with shallow to moderate soil rooting depths, moderate water stress, modest nutrient levels, and the cool climate and long growing season that allows a diverse amount of wine grapes to flourish. It’s no wonder why this area was identified so long ago as a prime area to grow some of the first commercially available wine grapes and wines in not just Paso Robles, but California. Today there are approximately 20 wineries in the 35,000-acre area that is the Templeton Gap District.

PC: Peter Schroeder III | Photographer/Videographer | Licensed Drone Pilot