This is most likely a parade for Cavalcade of the Valleys (precursor to the Evergreen State Fair), which was held Sept. 11-14. The back of the photo is dated 1941. The photo looks north at the 100 block of East Main Street showing Speaks Cash Feed Store and the White Spot Café.
Monroe Historical Society Photo 1268. If you know more about this picture, please contact the Monroe Historical Society at (360) 217-7223.