Grand Canyon Caverns, Arizona

Grand Canyon Caverns
Ŧathiil Ñwaʼa
Cave popcorn at the Snowball Palace in Grand Canyon Caverns
Location	Peach Springs, Arizona, United States
Depth	210m
Length	60 miles
Discovery	1927
Geology	Limestone

The Grand Canyon Caverns (Havasupai: Ŧathiil Ñwaʼa or Ŧathiil Ñhaʼa,35°31′44″N 113°13′54″W / 35.52889°N 113.23167°W / 35.52889; -113.23167Coordinates: 35°31′44″N 113°13′54″W / 35.52889°N 113.23167°W / 35.52889; -113.23167), located just a few miles east of Peach Springs, Arizona, lie 210 feet (64 m) below ground level. They are among the largest dry caverns in the United States. Dry caverns compose only 3% of caverns in the world. Because of the lack of water, stalagmites and stalactites are rare in the caverns. Air comes into the caverns from the Grand Canyon through 60 miles (97 km) of limestone caves, a fact discovered when red smoke flares were ignited in the caves, and two weeks later, red smoke was seen protruding from vents, near Supai, Arizona, in the Grand Canyon.

During the Mississippian Period, 345 million years ago, the southwestern United States was covered by ocean. Skeletons of sea life settling to the depths, created a mud with a high percentage of calcium. This eventually hardened into the limestone bedrock seen in the caverns today. Over millions of years, the bedrock was pushed up to over 5,000 feet (1,500 m) above sea level.