The Changing of the Guard
A new era for Rock Creek Park and related parklands began on August 10, 1933. An executive order effective that date, signed two months before by President Franklin D. Roosevelt, abolished the Office of Public Buildings and Public Parks of the National Capital and the Rock Creek and Potomac Parkway Commission and assigned their functions to the Office of National Parks, Buildings, and Reservations in the Department of the Interior. The Office of National Parks, Buildings, and Reservations was a new name for the National Park Service and one that proved temporary: the designation employed since the bureau's creation in 1916 was restored in an Interior appropriations act approved March 2, 1934. 
The administrative shift was part of a larger reorganization of the executive branch ordered by President Roosevelt during his first months in office (his action having been authorized in legislation signed by Herbert Hoover on his last full day as president). As it affected the National Park Service, the major aim of the reorganization was consolidation of the national monuments and battlefield parks administered by three government departments under one. Horace M. Albright, the enterprising young director of the Service, was chiefly interested in obtaining the parks and monuments of the Agriculture and War departments; but he did not object when Lewis W. Douglas, Roosevelt's budget director, drafted the executive order to include the Washington parks. A skilled political operator, Albright knew that possession of these parks would further enhance the Service's visibility among members of Congress and other national leaders. 
Under the National Park Service, Rock Creek Park and its adjuncts became components of National Capital Parks. The term denoted the administrative branch of the Service formed to manage the Washington area acquisitions as well as the parks themselves collectively. National Capital Parks inherited most of the civilian employees of the Office of Public Buildings and Public Parks, including Francis F. Gillen and Frank T. Gartside. Gartside acted as NCP superintendent for the first two months of the new administration, whereupon C. Marshall Finnan, formerly superintendent of Mesa Verde National Park, received the permanent appointment.
Finnan stayed through July 1939. Gartside, Edmund B. Rogers, and Gillen successively acted in the position during the interval to January 1941, when Irving C. Root took the job. Root, who had been chief engineer with the Maryland-National Capital Park and Planning Commission, was superintendent until July 1950. He was followed by a line of career Park Service managers: Edward J. Kelly through April 1958, Harry T. Thompson to February 1961, T. Sutton Jett to January 1968, I. G. (Nash) Castro to September 1969, Russell E. Dickenson from December 1969 to October 1973, and Manus J. (Jack) Fish, Jr., from then until this writing. From 1962 to 1969 and from 1976 to date, National Capital Region replaced National Capital Parks as the umbrella organizational term, and the head of the office was titled regional director.
Like most components of National Capital Parks, Rock Creek Park was not treated as a discrete unit of the National Park System for many years after it came under National Park Service administration. As a sub-unit of NCP it did not have its own superintendent and staff. Maintenance workers, park police officers, and others were detailed regularly to duty there, however, and the person assigned to supervise park maintenance was sometimes termed superintendent, as under the predecessor organizations.
Joseph J. Quinn, another legacy of Public Buildings and Public Parks, was chief of NCP's Rock Creek Park Division in the early 1940s and was called superintendent of the park in the mid-1950s. Keith R. Polhemus filled his role in 1958 as Chief, Rock Creek Park Section. In 1965 three new administrative divisions were established within the National Capital Region, and Rock Creek Park came under National Capital Parks-North, headed successively by Superintendents Joseph Brown, Julius A. Martinek, and Joseph Antosca. The three divisions were reduced to two in July 1972, Rock Creek being assigned to National Capital Parks-West under Superintendent William R. Failor, then Luther C. Burnett.
In 1975 the National Park Service listed Rock Creek Park as a separate unit of the National Park System, giving it the same nominal status as Yellowstone and Yosemite.  It did not yet have the same degree of administrative autonomy: when National Capital Parks-West was abolished that year, the park reverted to a division in the National Capital Parks headquarters managed by James J. Redmond. An administrative reorganization in October 1976 brought to the Rock Creek Division Pinehurst Parkway, Soapstone Valley Park, Melvin C. Hazen Park, Klingle Valley Parkway, Normanstone Parkway, Dumbarton Oaks Park, Montrose Park, Beach Parkway, and Blair Portal--tributary and other bordering reservations recently under George Washington Memorial Parkway and National Capital Parks-East jurisdiction. With its effective boundaries thus enlarged, Rock Creek Park lost its division status and became a distinct organizational entity in August 1977, and Redmond became a full-fledged park superintendent. Upon his untimely death in August 1983 he was succeeded in that capacity by Georgia A. Ellard.