Lock and Dam No. 17 is a lock and dam located near New Boston, Illinois on the Upper Mississippi River near river mile 437. Its main lock is 110 feet (33.5 m) wide and 600 feet (182.9 m) long with its bottom at an elevation of 518 feet (157.9 m). Normal pool elevation behind the dam is 536 feet (163.4 m). The movable portion of the dam is 1,121 feet (341.7 m) long and consists of 3 roller gates and 8 tainter gates. In 2004, the facility was listed in the National Register of Historic Places as Lock and Dam No.