Highland. 1 City (1990 pop. 34,439), San Bernardino co., SE Calif., in a citrus-grove area at the foot of the San Bernardino Mts. It has citrus-packing plants and some light industry. Highland developed with the growth of agribusiness and aircraft industries in S California. Norton Air Force Base, which was adjacent to the community, closed in 1994. 2 Town (1990 pop. 23,696), Lake co., extreme NW Ind., in the Chicago metropolitan area; settled 1850 as Clough Postal Station, name changed to Highland in 1888, inc. 1910. Manufactures include dairy products and mineral granules for sandblasting.