[3] The term "Great Plains", for the region west of about the 96th or 98th meridian and east of the Rocky Mountains, was not generally used before the early 20th century.

Nevin Fenneman's 1916 study, Physiographic Subdivision of the United States,[7] brought the term Great Plains into more widespread usage.

As the Farallon plate was subducted into the mantle beneath the region, water trapped in hydrous minerals in the descending slab was forced up into the lower crust above.

Within the crust, this water caused the hydration of dense garnet and other phases into lower density amphibole and mica minerals.

The combination of oil, natural gas, and wind energy, along with plentiful underground water, has allowed some areas (such as West Texas) to sustain a range of economic activity, including occasional industry.

For example, the ASARCO refinery in Amarillo, Texas has been in operation since 1924 due to the plentiful and inexpensive natural gas and water that are needed in metal ore refining.