The Canadian Pacific Railway (CPR), a transcontinental line, took control of the Duluth, South Shore & Atlantic in 1888. In 1892-94, CPR funds financed the construction of the DSS&A westward from the Keweenaw Peninsula to Duluth. During the 1890s, the
timber industry reached the peak of its operations on the Lake Superior shoreline properties adjacent to the DSS&A's new mainline, shipping old-growth white pine. After white pines were exhausted, local cutters began to turn to high-quality hardwoods such as sugar maple, and then to pulpwoods such as paper birch and aspen. At the height of the railroad's operations in 1911, the DSS&A operated of track, of which were main line and were branch lines and trackage rights. The railroad operated 3,121 pieces of rolling stock, including 82 locomotives, 67 passenger cars, 35 cabooses, and 2,957 freight cars. In 1913 the DSS&A's freight operations peaked at almost 1 million short tons (900,000 metric tons), of which more than half were forest products. In the late 1910s, timber yields began to decline all over the Upper Peninsula. This was a blow from which the DSS&A could not recover as an independent nameplate. Its story from 1920 onwards was that of the American railway industry as a whole, with negative factors intensified by unfavorable local business conditions in northern Michigan. In 1957, the State of Michigan opened the
Mackinac Bridge, a long suspension bridge carrying an all-weather hard road across the Straits of Mackinac into the Upper Peninsula. The DSS&A responded by ending its remaining passenger rail service in January 1958. In 1961, its Canadian owners merged it with the
Minneapolis, St. Paul and Sault Ste. Marie, and the DSS&A became part of the
Soo Line. ==Nicknames and challenges==