13706 State Hwy M,
Photo taken on March 2, 2016
Missouri Highway 21 Series
Hughes Mountain is a peak in the St. Francois Mountains Range of southeastern Missouri. Hughes Mountain is formed of extrusive rhyolite which fractured into vertical joints when it cooled, creating polygonal columns. These columns have from four to six sides and are up to three feet (0.91 m) tall. When viewed from above they resemble a honeycomb.
Columnar jointing is not limited to rhyolite formations. The Devils Honeycomb is a smaller example of the sort of columnar jointing found at Devils Tower National Monument in Wyoming, Devils Postpile National Monument in California, and the Giant's Causeway near Bushmills, Northern Ireland.
August 28th, 2019
Viewed 66 Times - Last Visitor from Beverly Hills, CA on 02/28/2020 at 3:24 AM