Terroir is the foundation of identifying wines by the point of origin, or appellation, for the grapes or other fruit used to make the wine. In the United States, the federal Tax and Trade Bureau (TTB), that regulates and supervises the production of wine and alcoholic beverages, designates American Viticultural Areas (AVA) to denote “a delimited, grape-growing region distinguishable by geographical features.”
Colorado’s wines will taste much different than wines from Napa Valley or Carneros in California, Bordeaux in France, the Mosel Valley in Germany or the Barossa Valley in Australia. Because Colorado’s vineyards are the highest in North America (4500 to over 7000 feet above sea level) and only slightly lower than some of the vineyards in Argentina, because our humidity is very low and our soils quite alkaline, our wines are unique. If you’ve ever spent time in Colorado, you know that our microclimates are more micro than most places—weather varies significantly from one plateau to the valley right beside it.
So the TTB has designated two AVAs in Colorado, which by no coincidence are located around the same areas where Colorado grows some of the greatest peaches, cherries, apples, pears and apricots in the world:
• The Grand Valley AVA, along the Colorado River, once called the Grand River, forty miles east of the Utah border—begins where the mouth of DeBeque Canyon opens onto the lush green oasis along the valley floor at Palisade, sheltered by the largest flattop mountain in the world, Grand Mesa, the AVA then spills up onto East Orchard Mesa and Orchard Mesa along the south bank of the river, and stretches right to the foot of the Colorado National Monument west of Grand Junction. Elevations range here from just over 4000 feet above sea level to over 4500. DeBeque Canyon and the Colorado River provide constant breezes to cool this area in summer and warm it up during the sometimes harsh winters. The chalky, south-facing Bookcliff Mountains reflect solar energy onto the valley floor, making for some great conditions for Syrah, Viognier and other Rhone varietals, as well as the Bordeaux grapes, especially Cabernet Franc, that flourish on the slightly higher and cooler Orchard Mesa. This was the site of Colorado’s first grape industry that began in earnest in the 1880-1890s. The Grand Valley gets as many [degree days] as Napa Valley, Tuscany or Bordeaux, but in a shorter period of time. Due to the similarity of climate with the foothills of the Pyrenees Mountains in Spain, Tempranillo also is proving to be well suited to this region.
• The West Elks AVA follows the North Fork of the Gunnison River from the old mining town of Bowie, through Paonia and Hotchkiss until it reaches the “dobies,” a barren, moonscape of adobe looking geological irregularities that separate Delta, Colorado and the Uncompahgre Range from the fertile basin to the east, nestled at the foot of the West Elk Mountains. As the elevation here ranges from about 5400 up to 7000 feet above sea level, the mild growing season starts about two weeks later and has 30% fewer days between the last spring frost and the first fall frost than does the Grand Valley. Consequently, this very picturesque valley features many of the central European grape varieties quite successfully, such as Riesling, Pinot Gris and Pinot Noir.
Several other areas in Colorado also produce grapes and other fruit used for wine, though they have not yet been designated as an AVA:
• McElmo Canyon and Montezuma County: McElmo Creek runs due east from Cortez, 10 miles east of Mesa Verde National Park. Not only do grape growers here frequently have to work around archeological ruins and pottery shards, but the climate can be just as challenging for growing grapes as it was for the Ancestral Puebloans trying to grow corn.
• Surface Creek or South Grand Mesa: Surface Creek flows down the south slope of Grand Mesa in Delta County, through Cedaredge and Eckert, but has never eroded into the geological substrates (staying instead on the geological “surface”). Geographically midway between the Grand Valley and the West Elks AVAs, the Surface Creek area splits the climatic difference between those regions as well. Consequently, Merlot and Riesling are strong players here.
• Fremont County lies in the shadow of Pikes Peak, which dominates the landscape as you drive south from Denver to Colorado Springs. Yet this 14,110 monolith protects the neighborhood of Cañon City and Penrose from damaging icy weather patterns that plunge the rest of Colorado’s Front Range into a deep freeze when they dip down from the Canadian Arctic. The Arkansas River also tempers the climate of this oasis keeping it warmer in the winter and cooler in the summer than the rest of the Eastern Plains of Colorado, even though it has some vineyards planted up to 6900 feet.
• Olathe and Montrose Counties produce world famous Olathe Sweet Corn. The same soil and climate that nurture that agricultural wonder also yield some equally fabulous grapes and other fruits, avoiding the extreme winter temperatures that can impact the other parts of the state.
• The Front Range (east of the Continental Divide) and the Eastern Plains average at least ten degrees colder during the winter than does the Western Slope (west of the Continental Divide), where most of Colorado’s grapes are grown. But those colder temperatures come with wider swings of temperature that allow Coloradans to frequently wear shorts one day in January and snow boots the next; to go skiing in the morning and golfing in the afternoon. The traditional European grape varieties don’t adjust as well as people to rapid temperature changes and extremes, so vitis vinifera vines are limited to the areas mentioned above. But many people are experimenting with native grape varieties (Norton), the French hybrids (Chambourcin, Seyval Blanc) or the new Minnesota hybrids (Marquette, Noiret) and are producing some tremendous wines. Look for more to come from this area.