Definition for Ogallala Aquifer
From Biology Forums Dictionary
The Ogallala Aquifer is a shallow water table aquifer located beneath the Great Plains in the United States. One of the world's largest aquifers, it underlies an area of approximately 174,000 mi² (450,000 km²) in portions of eight states: (South Dakota, Nebraska, Wyoming, Colorado, Kansas, Oklahoma, New Mexico, and Texas). It was named in 1898 by N.H. Darton from its type locality near the town of Ogallala, Nebraska. The aquifer is part of the High Plains Aquifer System, and rests on the Ogallala Formation, which is the principal geologic unit underlying 80% of the High Plains.