The commissioners were closely involved with their staff and consultants in all aspects of parkway land acquisition, planning, design, and construction. "The results accomplished in this undertaking," they asserted, "could not have been brought about had the Commission and its members been satisfied to exercise a mere supervisory administration over the project."(71) While the commissioners played an active role in the parkway’s design and conceptualization, they assembled an accomplished team of engineers, landscape architects, horticulturalists, and architects to provide technical expertise and oversee the parkway development process. Many of these men went on to play prominent roles in other twentieth-century park and parkway development projects.

The engineers and landscape architects recruited to work for the BPC came to their positions with a wide variety of experience. Jay Downer (1877-1949), the commission’s chief engineer and general secretary, was a Princeton-trained civil engineer who had worked for the Aluminum Corporation of American and served as the chief engineer for the Cape Breton Railroad Company in Nova Scotia. Downer worked for the BPC until 1925, except for a short break for World War I military service. After 1922, he also served as chief engineer of the new Westchester County Park Commission (WCPC). He also played an important role on the New York State Council of Parks. Downer was widely respected as an inspiring leader who preached the value of teamwork and encouraged his subordinates to express their creativity. Leslie Holleran, Deputy Chief Engineer, came to the BPC from the Board of Water Supply, where he had extensive experience working on the Catskill Aqueduct construction. Hermann Merkel (1873-1938), a German-trained forester, was the general superintendent of maintenance at the New York Zoological Society, where he directed landscape improvements and gained a reputation as a gifted plantsman and designer. This role undoubtedly brought him into contact with Grant and Niles, who hired him as the project’s chief forester and landscape architect. Serving as a part-time consultant to the BPC throughout the parkway project, he was primarily responsible for devising the parkway’s general landscape development plan. Gilmore Clarke (1892-1982) was hired as the superintendent of landscape construction when the planting and landscape development aspect of the project moved into high gear. A Cornell graduate working for the Hudson County Park Commission in New Jersey, Clarke had impressed Niles and Merkel, who convinced him to join the project team in 1916. After a brief interlude for war service, Clarke worked for the BPC until 1923, when he joined the newly formed WCPC as the agency’s chief landscape architect. Clarke became one of the twentieth-century’s most prominent parkway designers. In addition to his work with the WCPC on the Sawmill River Parkway, Hutchinson River Parkway, and other county developments, he served as a consultant to the federal government on such important projects as Mount Vernon Memorial Highway, George Washington Memorial Parkway, Blue Ridge Parkway, and the Baltimore-Washington Parkway. He left the WCPC for private practice in 1934. His firm Clarke and Rapuano designed the Palisades Parkway and executed many important landscape design projects throughout the New York metropolitan region. Designing Engineer Arthur Hayden was transferred to the BPC from the New York State engineer’s office. Clarke noted that Hayden had an exceptional "sensitivity to aesthetic matters" that was unusual for engineers. His work in devising the rigid-frame bridge had a profound impact on the Bronx River Parkway and subsequent parkway and highway developments. Counsel Theodosius Stevens worked for the BPC for many years before the state civil service commission transferred him to the Long Island Park Commission so that commission could benefit from his experience. Even after his transfer, he was willing to consult for the BPC when necessary.(72)

(71)Bronx Parkway Commission, Report, 1918, 36.
(72)Gilmore Clarke, "Jay Downer, A Biographical Minute," Landscape Architecture 40 (January 1950): 79-80; "Obituary: Hermann Merkel," New York Times, 1 March 1938; Domenico Annese, "Gilmore Clarke," in Pioneers of American Landscape Design, eds. Charles Birnbaum and Robin Karson (New York: McGraw Hill, 2000), 56-60. Clarke and Downer assisted the National Park Service in the early stages of the Blue Ridge Parkway project, but withdrew from the development team when the Department of the Interior was unwilling to meet their salary demands (see Richard Quin, "Blue Ridge Parkway," HAER No. VA-NC-42, Historic American Engineering Record, National Park Service, U.S. Department of the Interior, 1997, 33-37; for Clarke’s involvement in Mount Vernon Memorial Highway and George Washington Memorial Parkway, see Timothy Davis, "George Washington Memorial Parkway," HAER No, VA-69, National Park Service, U.S. Department of the Interior, 1994/98); Frederick Gutheim, Worthy of the Nation: The History of Planning for the National Capital (Washington, D.C.: Smithsonian Institution, 1977), 186; Bronx Parkway Commission, Final Report, 1925, 53, 61-62; Thomas J. Campanella, "MOTORElysium: Gilmore D. Clarke and the Garden for the Machine, Westchester Parks and Parkways, 1916 to 1934" (Master’s Thesis, Cornell University 1991), 76-82; Bronx Parkway Commission, Minutes, September 23,1924, 144-49.