Bethlehem Township municipal offices are located at 405 Mine Road, Asbury NJ 08802; phone: 908-735-4107.
Bethlehem Township was established about 1765 and incorporated in 1798 becoming one of New Jersey's original 104 townships.
The original inhabitants of the land were the Lenni-Lenape, who have left behind many artifacts, but little in the way of preserved structures or population. While European exploration of the area started in the late 17th century followed by minor colonization of the area, the population grew most dramatically in the early part of the 19th century. The settlers were predominantly Dutch from Holland followed to a lesser degree by French, Germans, Scots, English, and Irish. The diversity of settlement, the evolution of the local economy, and the relatively slow development of the area within the last century has left behind an eclectic array of historical sites.
Agriculture has been the predominant economic force throughout much of Bethlehem Township's history. As such, there are many surviving farmsteads, farmhouses, and various outbuildings. Aside from the age of the surviving structures, they are also valued for the link with historically important families within the Township. The wide availability of building materials, most importantly stone and wood followed by brick, and the influence of various northern European styles leads to a diversity of forms of significant architectural value. In total, 39 historical sites were identified in the 1979 Hunterdon County Master Plan. In addition to rural structures, village life has been important in the Township for a long period including various services associated with agricultural use such as blacksmithing and milling. The village of West Portal, variously known as Bethlehem and West End, is an important historical district within the Township. Within this district, there are 24 documented historical sites including houses, municipal buildings, and commercial buildings.
The second important commercial enterprise within the Township was the mining of iron ore. A 1988 report identified 11 mine sites in the hilly terrain of the southern tier of the Township. While iron mining was loosely documented in the 18th century, mining reached its peak from 1850-1890. Commercial mining declined in the Township as veins were depleted and the mining industry boomed in the western states. Mining brought about the growth of villages within the Township and increased transportation infrastructure.
Mining required the use of the rail system, which included two competing rail systems the Lehigh Valley Railroad and the Central Railroad of New Jersey. Today there are 4 recognized historical railway bridges, including the Musconetcong Tunnel, considered an engineering feat at the time of completion. In addition, there were improvements in the roadways as well, including 4 surviving bridges noted for the use of the Pony truss and masonry.