Since its 1966 beginning, operating under the original ownership and administration of the Oklahoma City Geological Society, the now independent Mid-Continent Geological Library (MCGL) has grown into the premier repository of geological and historical well data in the mid-continent region of the United States, supporting the research by members of the petroleum industry and other members of the public interested in geological history. In addition, the MCGL is currently operating and further developing the MCGL Digital Library, enabling access to certain library records via the internet (separate subscription required).