Prior to 1889, the lot on which the Seehorn-Lang Building sits was vacant. Spokane businessmen Gile O. Bump and C. W. Ide purchased the property and deeded it to the Spokane Storage Company, which built a storage structure on the site. However, the structure would quickly be replaced after the Great Spokane Fire by the brick Seehorn-Lang Building. Built in 1890, the original structure of the building was smaller than it is at present, occupying only two-thirds of its lot. Early tenants were food distributors and packing companies. By 1910, the building had been expanded north to fill nearly its entire lot.[2]
Also in 1910, prominent early Spokane businessman Elihu "Billy" Seehorn moved his Seehorn Transfer and Storage Company into the building. Though the company would leave the building 15 years later and move a block to the east, the Seehorn-Lang Building would retain the Seehorn name in public use. The title for the property was acquired by local businessman John Lang in 1925, giving the building the second part of its hyphenated name.[2]
When the Seehorn company moved out in 1925, alterations were made to the building. A new facade along Lincoln Street was constructed, which as of 2022 remains to this day. The interior was also renovated, converting the building into a retail sales space with nine rooms for lease. John Lang died in 1926, and ownership of the building was passed to his widow, Wilhelmina, who managed the property until her death 14 years later. At that time, in 1940, the Lang's son, Otto Lang took over ownership of the property until his death, when it then passed to his widow Mary Lang.[3][2] The Lang family owned the building until 2017, when Deborah Lang-Westwood, John Lang's great-granddaughter, sold the building to Avista Utilities. Avista, through its predecessor company Washington Water Power, had owned the adjacent Central Steam Heat Plant for nearly 100 years.[4] Avista sold both the Seehorn-Lang Building and the Steam Plant, which together form the Steam Plant Square, to Spokane developer Jerry Dicker in 2021.[5]