Find Your Park
Road Trip
Activities
Nature
Hot Springs National Park Geology
Hot Springs National Park is in the Zigzag Mountains, a small range of the Ouachita (Wash'-i-tah)Mountain system in the Interior Highlands, which form the only major topographic relief for a vast area of the midwestern and south-central United States. The topography was formed in late Paleozoic times (400 million years ago) by tremendous geological forces that acted to uplift, fold, fault, fracture, and harden inland seabed sediments. Subsequent erosion has led to the formation of the present ridge and valley landscape. The narrow steep ridges of the Zigzag Mountains, are capped with novaculite rock outcrops. These outcrops are unique to the Ouachita Mountains, and the finely grained structure of the novaculite is known for its superior quality as a natural whetstone.
Maine ocean islands provide the only nesting sites for Atlantic puffins in the United States. Eastern Egg Rock in the midcoast region, Seal Island and Matinicus Rock at the mouth of Penobscot Bay, and Machias Seal Island and Petit Manan Island off the downeast coast provide habitat for more than 4,000 puffins each summer.