Complex sentence: The high point is on Mine Mountain in Bernardsville, at approximately 860 feet (262 m) above sea level; the lowest point is just above sea level on the Raritan River at the Middlesex County line.
Split into simpler sentences: The high point is on Mine Mountain in Bernardsville, at approximately 860 feet (262 m) above sea level. The lowest point is just above sea level on the Raritan River at the Middlesex County line.