This is a very unique photo along with a brief synopsis from the Oregon State Archives showing the melding of the transportation of the past to the ways of the future.
"Who would have thought that in our collection of photos there would be one of a mule driven wagon freight train being buzzed by an early American Airlines Boeing 247 airplane? We had a patron in the Archives last Friday that discovered this gem. What an awesome photo! If you look closely you can see that the guy riding the mule closest to the wagons has what appears to be his hat in his hand. From the excellent and informative comments we received regarding this photo it appears that this photo was likely taken around the 1930's or 1940's. As Laurel Tofflemire noted the mule drawn wagons in this photo is more likely a "mule 'freight train' which generally used 10 to 20 mules depending on the weight of the load. These look like Stockton or Studebaker built high sided wagons which served as freighters with the tool boxes on the front end gate and feed boxes behind instead of the Oregon Wagon Trail Conestoga.
When hauling ore they were usually not covered but in Oregon the load may have been wheat. The "Mule skinner" riding the 'wheel mule' would control the entire team with one rein called a 'jerk line'."