Bethlehem is located in the Lehigh Valley in eastern Pennsylvania. The initial settlement was formed on the northern bank of the Lehigh River, though the city expanded across to the south bank in the nineteenth century. Containing a vast supply of natural resources, Bethlehem and the surrounding area contain coal, iron ore, and rich soil. The rolling hills, numerous streams, and temperate weather make the area conducive for farming. The Lehigh Valley is surrounded by the Delaware River to the east, South Mountain to the south, and the Blue Mountains on the west and north. Bethlehem Steel is located south of the River and north of 4th street. It extends from the bridge eastward, beyond the city limits.