My quest to visit more Texas state parks this year took me up to Longhorn Cavern, located off U.S. 281 near Marble Falls. State of play: The cavern was formed by an underground river system, a rarity ...

Active drilling rigs in New Mexico. More than Wyoming, North Dakota and Utah combined. Most are located in Eddy County, home of Carlsbad Caverns National Park. Carlsbad Caverns is home to some of the ...