Carménère has also been established in Eastern Washington's Walla Walla Valley and in California, United States. In the 1980s, Karen Mulander-Magoon, the co-proprietor of Guenoc and Langtry Estates Winery, in California's Lake County, brought the grape to the vineyard. This was a joint effort with Louis Pierre Pradier, "a French research scientist and viticulturalist whose work involved preserving Carménère from extinction in France." Once the vines were quarantined and checked for diseases they were legalized for admission into California in the 1990s, where they were cloned and planted.