|The Huntington Beach Public Library on Triangle Park is associated with events that have made a significant contribution to broad patterns of the City's local history, in the area of community planning and development (Criterion A). Established as a recreational park in 1912, just three years after the incorporation of Huntington Beach, Triangle Park became part of the City's early-20th century Civic Center campus in the Downtown Core in the 1920s. The park , too , supported the addition and adjacent construction of several municipal buildings, the last of which, the International Style Huntington Beach Public Library (1950-1951), is still extant. The Huntington Beach Public Library on Triangle Park sustains an important link to the City's formative years and early-20th century efforts in community planning and development, which endured to support pioneering methods in construction and new expressions of postwar Modern architecture in the mid-20th century. On the state and national level in the areas of architecture, engineering, and industry, the Huntington Beach Public Library on Triangle Park embodies the principles of postwar Modern design and the distinctive characteristics of site-cast , concrete tilt-up construction from the early postwar period, particularly that of public libraries. The property furthermore represents the work of masters, James Edward Ted McClellan, Denver Markwith, Jr., and Jack Hunt MacDonald, who with a uniquely comprehensive design and building approach, were major contributors in this method of construction (Criterion C). In general, their contribution in site-cast, concrete tilt-up construction, and their promotion of efficient and economical techniques, provided an important aid in Southern California's growth and rise to dominance as a center for manufacturing, distribution, logistics, and trade. This innovative method was revolutionary in the late 1940s and early 1950s, and has become an important segment of the construction industry in the present day. The library's three-hinged arch str uctural system was unusual for 1950-1951, and hence, the building's design broke new ground in its time as Southern California led the nation in the initial commercial expansion of site-cast, concrete tilt-up construction immediately following World War 1. The library has been recognized among its peers by construction industry leader, Hugh M. Brooks, Jr., as an excellent surviving example of an innovative application of the tilt-up method and the use of cast-in-place and precast concrete components for that time period. The building also has been endorsed by preservation professionals, Galvin Preservation Associates , in a recent survey evaluation and finding of eligibility as an individual property for listing in the National Register of Historic Places.