An extensive planning effort by the City of Sioux City and its partners have resulted in an annexation of approximately 400 City-owned acres, the construction of vital utility infrastructure resources (including a new electric substation and 10mgd water plant), and planning and development of an extensive internal road network. Southbridge also features a drop and pull yard rail yard served by Union Pacific. The yards design is completed, funding secured, and will be constructed in 2014. The area lying immediately south of the Sioux City Gateway Airport that is planned for mixed use development including recreation, bio-tech, value-added agriculture, wind energy, logistics, advanced manufacturing, and research. Site C is the former home of a 27-hole golf course which was recently purchased and annexed by the City. For additional information contact the Sioux City Economic DevelopmentLocated on the southern edge of Sioux City, Iowa, between the Missouri River and Interstate 29, the entire Southbridge area encompasses nearly 10,000 total acres of flat, developable land.Located on the southern edge of Sioux City, Iowa, between the Missouri River and Interstate 29, the entire Southb Located on the southern edge of Sioux City, Iowa, between the Missouri River and Interstate 29, the entire Southbridge area encompasses nearly 10,000 total acres of flat, developable land.