The six–team Independent level Upper Peninsula League consisted of franchises based exclusively in Michigan.
The Calumet Red Jackets, Hancock, Houghton, Ishpeming, Marquette Undertakers and Negaunee teams were the charter members.
Houghton won the 1890 Upper Peninsula League championship with a 23–12 overall record in the six–team league, as the Hancock and Negaunee franchises folded during the season.
The Calumet Red Jackets won the championship with a 36–24 record.
[1][4][5] 1890 Upper Peninsula League standings Hancock and Negaunee disbanded mid–season 1891 Upper Peninsula League standings