Wonders of nature. The Oneonta Gorge is in the Columbia River Gorge in the American state of Oregon. The U.S. Forest Service has designated it as a botanical area because of the unique aquatic and woodland plants that grow there. Exposed walls of 25-million-year-old basalt are home to a wide variety of ferns, mosses, hepatics and lichens, many of which grow only in the Columbia River Gorge. Oneonta Gorge has been described as "one of the true dramatic chasms in the state."