was assigned as the construction's head engineer 1883 - After 22 months of intensive work, the Stone Arch Bridge was completed 1885 - The Union Depot at the heart of Minneapolis was completed and substantially increased the passenger volume 1907-1911 - Renovations were done to improve the bridge's drainage system and strengthen its structural support in order to transport heavier loads 1925 - Another renovation conducted to increase the width to allow bigger trains that would house more passengers 1961- 1963 - The lock and dam was built at St. Anthony falls which required arch number 13 and 14 to be replaced with a 200-foot Warren truss and allow barges to pass 1965 - The bridge underwent renovation when the Mississippi River flooded, causing the seventh pier to sink about 14 inches 1971 - The bridge became part of the National Register of Historic Places 1978 - The last passenger train crossed the Stone Arch Bridge 1989 - The bridge was bought by the Hennepin County Regional Railroad Authority 1992 - The ownership was transferred to Minnesota Department of Transportation 1994 - The bridge was converted into a biking/walking path by the Minneapolis Park Board Design and construction The Stone Arch Bridge, commissioned by James J Hill and designed by Charles C Smith, was built between 1882 and 1883. Hill originally intended to build an iron bridge spanning the Mississippi at Nicollet Island, but Smith discovered that pursuing that design would be detrimental to St Anthony Falls’ eroding sandstone. Smith's design was pioneering and the signature arches were designed to account for the falls and the surrounding topography. The stone used to make the bridge was locally sourced, including granite from Sauk Rapids for the piers and magnesium limestone from Mankato and Iowa for the upper portion. In the 130 years of its existence the bridge has undergone a number of upgrades and repairs. In 1925 the width of the bridge was increased to allow for larger railcars. Then in 1994 the bridge was converted to a pedestrian walkway. Heritage trail plaque A plaque near the bridge explains that the bridge was built for the Manitoba Line (St. Paul, Minneapolis and Manitoba Railway), which would be used to bring wheat from the Red River valley and Canada to the Minneapolis mills. It remains as a monument to James J. Hill, his vision, and is a National Historic Civil Engineering Landmark.