Spokane's minor league history dates all the way back to 1892 when it fielded a team in the Pacific Northwest League. The nickname "Indians" was introduced in 1903 when Spokane joined the Pacific National League, a predecessor to the Pacific Coast League and an elite minor league of the period -- equivalent to Triple-A today. The Indians lasted only two seasons at that higher level before dropping to the Class B Northwestern League, which folded during WWI.
In 1937, Spokane became a charter member of the Class B Western International League (WIL), the predecessor of the Northwest League. They played at Ferris Field from 1937 through the beginning of WWII in 1942, and again from 1946 until folding during the 1954 season.
Spokane was a charter member of the Northwest League, which debuted in 1955 as a Class B league. These Indians also played at Ferris Field but folded after just two seasons, and the city went without minor league baseball in 1957.