JA Thurmond, Levi McGlothlin and Ray Jordan were employed as testers for various companies in Gray County in the early 1940s. Thurmond formed his own gas testing company in 1946 in Lefors and started with four customers. Three years later McGlothlin became Thurmond's partner in 1949. Jordan went to work for the company in 1952. Thurmond-McGlothlin, Inc. was moved to Pampa to office on Price Road in 1955 .

In 1963 Jordan became a partner and president of the company. Jack Chisum came to work in 1958. He became a working partner in 1968. In 1962 the Pampa office moved to 921 W. Harvester and in 1978 new offices were built at 1428 N. Banks. The firm's first branch office was opened in Ardmore, Oklahoma. By 1991 Thurmond-McGlothlin also had offices in Hennessey, Woodward, Edmond and Willburton, Oklahoma and Roosevelt, Utah with boasting rights to being the nation's largest gas measurement and testing service company.

Thurmond-McGlothlin is known industry wide as the one company providing a complete field and laboratory program in its testing services. The Thurmond-McGlothlin concept of full service begins with a gas management program engineered to deliver information and data accurately and on time.

Thurmond-McGlothlin offers chart integration and computing, gas well potential testing, GPM testing , orifice meter testing and overhaul, gas surveys and the services of a fully equipped petroleum laboratory.

The company can coordinate and supervise gas property management, normal lease and well maintenance, remedial recommendations, work contracting and supervision, filing all state required tests, preparing state required reports, and measurement auditing.