[1] The Eau Claire Lumbermen, Milwaukee Brewers, Minneapolis Millers, Oshkosh and St. Paul Freezers teams joined Duluth in beginning league play on May 6, 1886.
With a record of 46–33, Duluth finished 1.5 games ahead of the second place Eau Claire Lumbermen when the Northwestern League season schedule ended on September 30, 1886.
[9] Overall, Duluth (46–33) finished ahead of the Eau Claire Lumbermen (43–36), Oshkosh (39–39), St, Paul Freezers (37–43), Minneapolis Millers (36–42) and Milwaukee Brewers (35–43) teams in capturing the 1886 Northwestern League championship.
[14] Om May 11, 1887, after playing a game in La Crosse, Wisconsin, a boating accident on the Mississippi River claimed the life of Duluth player John Ake.
[16] Ake then attempted to swim the shore before Barnes and Earle could secure a rescue skiff, but after a couple strokes, Acke began to shout for help before slipping under the water.
The team finished in fifth place after the Lincoln Rustlers and Minneapolis Millers folded during the season and the Milwaukee Brewers left the league in August to join the American Association.
The Sioux City Cornhuskers won the league title with a 66–57 record, finishing 13.5 games ahead of Duluth.
[21] The Denver Mountaineers, Kansas City Blues and Omaha Lambs teams also played with Duluth in the league.