Commercial fishing followed the initial logging boom of the 1890s. Large-scale fishing operations began on the Rainy River as early as 1892. At its peak, in the late 1890s and early 1900s, roughly seven or eight large-scale fishing companies operated in the area, primarily on Crane Lake. The production of caviar, the eggs of lake sturgeon, was a major economic pursuit at this time. However, due to the great distance to markets, and the lack of refrigerated transport, these enterprises were relatively short-lived, although some remained in operation until the 1930s.
Small-scale family fishing soon developed as a result, with the largest number or licensed family operations in the area reaching 48 in 1910. These family operations depended on local auctions at Kettle Falls to sell their catch. Commercial fishing was banned on Kabetogama Lake in 1923, and by 1942 only 10 licensed family operations were active in the area. Evidence of fishing camps and net-tarring sites exist in the park today, including the Oveson Fish Camp (ca. 1950s) which has been determined eligible for listing on the National Register of Historic Places.