The Columbia Gorge American Viticultural Area, encompassing vineyards and wineries in Washington and Oregon, is a region of strong contrasts and distinct wine styles. Stark differences in rainfall, soils, and temperatures enable growers to produce a wide range of wine grape –varietals.

A busload of Pacific Northwest wine grape growers and vintners spent a day visiting the Columbia Gorge AVA in August as part of the Washington Association of Wine Grape Growers’ summer educational program. Each summer, the association takes an in-depth look at a different wine region, studying the soils, geology, climate, and wine grape varietals to learn about the breadth of wines –produced in the Northwest.

The Columbia Gorge AVA, billed as a "world of wine within 40 miles" by the Columbia Gorge Winegrowers Association, was approved in 2004, and is home to a dozen wineries and about 45 vineyards. Rainfall in the unique wine region ranges from a scant 10 inches to 60 inches a year. In the cooler sites, typical varieties include Riesling, Chardonnay, and Pinot Noir. Warmer sites, which can have temperatures around 100°F in the summer and have long growing seasons before
fall rains, do well growing varieties like –Cabernet Sauvignon, Zinfandel, Syrah, and Sangiovese.

"The rainfall increases one inch per mile as you go from east to west along the Columbia Gorge," said Dr. Alan Busacca, who served as tour guide.

"Those kind of rainfall and climate changes are really hard to wrap your brains around," said Busacca, a former Washington State University geology professor. Busacca is now president of Vinitas Vineyard Consultants, based in Hygiene, Colorado.

Busacca explained that geology in the region shows impacts of the giant Missoula glacial outburst floods, with landforms of steep canyon walls and soils of flood sediments. But Columbia Gorge vineyards that are above the flood levels, such as those on Underwood Mountain, are dominated by lava and mud flows from the volcano ancestors of Mount Hood and Mount Adams, he added.

Eastern boundary

Hot temperatures, with strong prevailing winds, are common on the eastern side of the AVA and require special canopy management to prevent sunburn. At vineyards surrounding Washington’s Maryhill Winery, timing is important when bringing shoots up to the wind-wires of the trellis, said Craig Leuthold, adding that shoots will break if they are brought up too early. "And if you’re too late, it’s like wrestling with a gorilla," he said.

Leuthold, owner of Maryhill Winery, which is on the Washington side of the Columbia Gorge, said retaining soil moisture was one of the biggest challenges to producing quality grapes in vineyards near Maryhill. "Wind, heat, and sandy loam soils make water a challenge," he said. "When you have several 100-degree days, coupled with 30 to 40 mile-per-hour winds, the water just disappears."

Maryhill Winery, which opened in 2001, receives 75,000 visitors each year and is in the top 20 wineries in the state in terms of size, annually producing about 50,000 cases, according to Leuthold.

Dan Gunkel of Gunkel Orchards in Maryhill, Washington, is one of the primary grape producers for Maryhill Winery. Gunkel noted that their vineyards typically attain more than 3,000 growing degree days, with less than ten inches of precipitation. Vineyards on the south slopes of the Columbia River bloom earlier and enjoy a longer growing season in the fall than inland vineyards. The Columbia’s large body of water also serves as a moderating influence during –freezing temperatures in the winter.

The wind is an ally when it comes to powdery mildew, Gunkel said, adding that they can get away with only spraying for mildew three times a year if the canopy –structure is maintained for airflow.

Western side

On the western side of the AVA and opposite end of the region’s rainfall spectrum is Celilo Vineyard, the oldest operating vineyard in the gorge area and one of the older vineyards in Washington State. The 70-acre vineyard, which was established in 1973, is on a southeast-facing slope of Underwood Mountain, an extinct volcano with breathtaking views of the Columbia River and the town of Hood River. Growing degree days average 2,400—much fewer than in vineyards planted on the eastern end of the gorge.

The vines at Celilo are trained to the modified Scott Henry trellis system to help control vigor. "We call it modified in case it’s not done perfectly," said vineyard founder and manager Rick Ensminger. The Scott Henry system divides the canopy into two fruiting zones (an upper and lower zone) with a window for airflow and sunlight.

"The vertical trellis system fits our situation of a lot of vigor and rain," he said. Rainfall varies, depending on the elevation of the vineyard, with the upper vineyard at Celilo receiving about 50 inches annually. All of the vines are farmed without irrigation.

Ensminger has not used any insecticides in the vineyard—yet. But mildew and gophers are major challenges.

Gophers love the extremely deep, porous volcanic soil that has few large rocks to get in the way of tunneling. After battling gophers for years with various methods, Ensminger now employs a professional trapper. In some months, the trapper has caught up to 800 gophers. The root-chewing rodents prefer young vines and young pear trees that are also under Ensminger’s management.

There was a time when they stopped planting any vines or trees because "it was like throwing cheeseburgers at them," he said. "We were losing hundreds of plants in a season."

About 25 wineries buy grapes from Celilo Vineyard, names that read like the who’s who winery list of the Northwest—Woodward Canyon, Ken Wright Cellars, Andrew Will, and Erin Glenn Winery, to name a few. Varieties grown in the upper reaches of the vineyard include Chardonnay, Pinot Gris, Gewürztraminer, and Pinot Noir. Through the years, Ensminger said they’ve learned what can and can’t be grown in their location.