Thousands of immigrants and adventurers traveled to Minnesota Territory in the 1840s by steamboat and humble wagon roads, but seasonal river conditions and rough dirt trails made journeys difficult, leading pioneers to demand better routes. In 1849, Congress provided $40,000 to build a military post road from Mendota to Wabasha, and the government soon created a network of four military roads near the navigational head of the Mississippi River that carried supplies, mail, and people year-round. One extended north through the St. Croix River Valley toward Lake Superior, another ran southeast to Wabasha along the western bank of the Mississippi River past ice-locked Lake Pepin, a third followed the Minnesota River Valley southwest through Mankato, and a fourth went north along the Mississippi River to Fort Gaines, now Fort Ripley. One of the few surviving sections is a 3,000-foot unpaved segment of the Mendota-to-Wabasha Military Road in Red Wing's Cannon River bottomlands, built between 1855 and 1858 with an elevated earthen roadway and bridges over the Cannon River and its bottomlands. After federal funding for the road ended in 1857, Goodhue County and Burnside Township assumed responsibility for the Cannon River section. In the early 1900s it became State Road 3, in 1921 it entered the state's trunk highway system and received a new concrete girder bridge, and in 1931 the state built a new section of highway west of the original route, leaving the old road outside the trunk system. Renamed Cannon Bottom Road, it later passed to Burnside Township and then to the City of Red Wing after consolidation in 1971; flooding and safety concerns led to its closure in the 1990s, the two short iron bridges were removed in 2012, and the concrete bridge over the main channel remains. This well-preserved fragment between Collischan Road and Cannon Valley Trail was listed in the National Register of Historic Places in 1991.