Created by an Act of the State Legislature on March 15, 1738 separating it from Hunterdon County, the county derived its name from Colonel Lewis Morris, then Governor of the Province of NJ. The county is known as the "Military Capital of the Revolution", and each of its 39 municipalities played some part in the war effort and contains something of historical importance to this day. Preserving this proud heritage falls to the Morris County Heritage Commission, Historical Society and numerous other groups.
The Township of Mount Olive was formed by an act of the New Jersey Legislature on March 22, 1871 from portions of Roxbury Township. Netcong was formed from portions of the township on October 23, 1894.
Budd Lake, a population of 8,968, is a census-designated place and unincorporated area located within Mount Olive Township. Flanders is an unincorporated area within the Township.