The Buffalo River is one of the few remaining unpolluted, free-flowing rivers in the lower 48 states offering both swift-running and placid stretches. The Buffalo National River encompasses 135 miles of the 150-mile long river. It begins as a trickle in the Boston Mountains 15 miles above the park boundary. Following what is likely an ancient riverbed, the Buffalo cuts its way through massive limestone bluffs traveling eastward through the Ozarks and into the White River. The national river has three designated wilderness areas within its boundaries.

The park's headquarters is located in Harrison, Arkansas, providing administrative services to the national river. The Tyler Bend Visitor Center, the main visitor center for the park, is located eleven miles north of Marshall, Arkansas. The park has two other visitor contact stations; the Pruitt Ranger Station, located five miles north of Jasper, Arkansas on Highway 7, and Buffalo Point Ranger Station, located 17 miles south of Yellville, Arkansas, on Highway 14.

Congress established Hot Springs Reservation on April 20, 1832 to protect hot springs flowing from the western slope of Hot Springs Mountain. This makes it the oldest area currently in the National Park System--40 years older than Yellowstone National Park. People have used the hot spring water in therapeutic baths for more than two hundred years to treat rheumatism and other ailments. The reservation eventually developed into a well-known resort nicknamed "The American Spa" because it attracted not only the wealthy but also indigent health seekers from around the world. Today the park protects eight historic bathhouses with the former luxurious Fordyce Bathhouse housing the park visitor center. The entire "Bathhouse Row" area is a National Historic Landmark District that contains the grandest collection of bathhouses of its kind in North America. By protecting the 47 hot springs and their watershed, the National Park Service continues to provide visitors with historic leisure activities such as hiking, picnicking, and scenic drives. Hot Springs Reservation became Hot Springs National Park by a Congressional name change on March 4, 1921.