PEPPERMINT Greenleaf Essential Oil Peppermint Oil in America is mainly grown and distilled in Oregon and Washington State. Peppermint Oil from the Williamette Valley of Oregon is unique for possessing fresh, green, cooling qualities with grassy undertones. Diffuse Peppermint Williamette Valley for an instant environment refresh. Each Greenleaf essential oil bottle holds 0.5 fl oz of 100% pure, natural, and undiluted essentials oils, and proceeds from this item are donated to organizations working to break the cycle of human trafficking.