Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 22C, § 5

There shall be within the division of field services two bureaus, which shall be designated as the bureau of eastern field operations and the bureau of western field operations. The head of each such bureau shall be designated by the colonel and shall hold such rank or temporary rank as the colonel may determine. The colonel may from time to time assign to each such bureau such uniformed members and other employees of the department as he may deem necessary to carry out its duties.