The Platteville Subdivision, also known as the Galena branch, was a railway line in the states of Illinois and Wisconsin.

[1][6] The line between Galena and Fennimore was converted to 1,435 mm (4 ft 8+1⁄2 in) standard gauge in 1882.

[7] The Chicago and North Western constructed a 2.7-mile (4.3 km) spur to Hazel Green, Wisconsin, in 1907.

[8] Amid bankruptcy reorganization, the Chicago and North Western began abandoning the line in 1939, starting with the section between Galena and Hazel Green Junction in 1939.

[11] In 1967 it was cut back to Cuba City, Wisconsin, and then abandoned altogether in 1980.