Berkshire Ridge Condos Jefferson is located in Oak Ridge section of Morris County. A total of 215 homes are in this complex built in the late 1980's. Berkshire Ridge is located in Oak Ridge section of Morris County. A total of 215 homes are in this complex built in the late 1980's. Sq. ft. ranges from 900 up to over 1,600. There are many different styles of units to choose from.