Company History

In October of 1928, Curtis Harold Guernsey Sr. founded a consulting engineering firm in a garage office adjacent to his home in Cherokee, Oklahoma. From humble, rural beginnings to a 150-strong employee-owned engineering, architecture and consulting firm today, a reputation for quality, service, capability and professional integrity continues to be our most valued asset and our foremost ambition.

From its beginnings in the 1920s and 30s, serving the infrastructure needs of Oklahoma municipalities GUERNSEY grew to a strong regional firm providing electric power engineering and civil infrastructure services to municipalities and rural electric cooperatives. 

During the war years, GUERNSEY lent its support to the war effort providing engineering services for stateside military installations. On one project, Mr. Guernsey rented a Tulsa office, hired every draftsman he could find and worked both day and night to complete a critical military project.

After the war years, GUERNSEY grew in its energy service offerings, designing numerous central electric generation stations throughout the Midwest. The 1950s and ’60s ushered in new opportunities in telecommunications and eventually the firm’s first architecture department.

The 1970s afforded the company an array of new opportunities. The architectural services continued to grow, construction management services boomed and the firm added to its energy portfolio by providing high-voltage electric transmission and substation design services, as well as regulatory and electric cost of service and rate analysis consulting.

1984:  Tinker AFB Building 3001 was destroyed by fire. GUERNSEY was selected to provide electrical and mechanical engineering support services. Getting the world’s largest aircraft maintenance facility back online in less than 90 days propelled GUERNSEY into the Department of Defense (DoD) market. The firm continues providing a full array of architecture and engineering services to the DoD throughout the U.S. 

During the 1980s, GUERNSEY also launched an environmental services and security division. These services continue today, successfully working with private industry, Fortune 500 companies, local, state and federal clients.

The birth of a new century and the celebration of its 75th Anniversary ushered in unprecedented growth. One new area GUERNSEY is leading the industry in is Petroleum and Petrochemical services. The re-tooling of the nation's refineries and a small group of highly skilled engineers and environmental scientists is quickly placing GUERNSEY on the map for this new service.

GUERNSEY carries forward its founder’s philosophy of recruiting and keeping the best people. This philosophy, as well as the company's history of treating clients and employees with integrity and honesty, is why GUERNSEY realizes continued success and steady growth. GUERNSEY employees accept an active role in determining the company's future as well as the communities' in which they live. This is evidenced by the firm’s spectacular array of diverse services and steady growth over time.