Natural gas in Colorado, northern New Mexico, and Utah is found in rocks ranging in age from Pennsylvanian to Eocene. Three types of gases are found in commercial quantity, namely, hydrocarbon, helium, and carbon dioxide. Comparatively little commercial development has occurred in this territory because the productive areas are isolated and far removed from markets. However, each of the three types of gases has been placed on the market from one area, or more, and many other areas of commercial importance have been proved. Natural hydrocarbon gas in commercial quantities has been proved in 31 areas, helium in 3 areas, and carbon dioxide in 8 areas. Actual commercial production of hydrocarbon gas has occurred in 15 areas, helium has been produced in 1 area, and "dry" -ice lants, to utilize carbon dioxide gas, have been built in 3 localities.

This paper is a brief summary of the known gas resources of parts of these three states, and describes the geologic and structural conditions under which the gases are found.