Marcia Monahan-Torres grew up in Chile, where she began her winemaking career in 1995 at Viña Cousiño Macul in Santiago. She then joined Viña Canepa, also located in Santiago, as assistant winemaker.

In 1996, Marcia came to the U.S. as part of the Communicating for Agricultural and Exchange Program. Her first winemaking job in California was as an enologist at Cardinale Winery in Napa Valley, and this was followed by assistant winemaker positions for Kendall-Jackson Winery in both Sonoma and Napa counties. Marcia was named winemaker for Pelton House in Knights Valley, Sonoma County, in 2006.

In 2010, Marcia became the winemaker for Matanzas Creek Winery in Santa Rosa, which produces Sauvignon Blanc, Chardonnay, and Merlot, among other varietals.

She lives in Knights Valley with her family. Marcia is known as a proponent of sustainable agriculture and organic viticultural practices.