When I first saw this image from the Vancouver Barracks I assumed they were doing a Civil War reenactment. But in 1900, cavalry and cannons were the primary weapons of war.
The Vancouver Barracks were closed in 2011. They were turned over to the National Park Service and are now known as the Fort Vancouver National Historic Site.
Horses and cavalry played an important role in World War I. There were large horse roundups in eastern Oregon and Washington to supply horses for the war.
Looks like a plowed field and you can see the River in the background.
Now this area is filled with a freeway, airport, railroad tracks, hotels, Fred Meyer.....
L.E. on 10th June 2019 @ 9:39am
and behind the PR, horses played an important role in WW II at least on Hitler's side, probably Stalin's also. .
Arlen L Sheldrake on 10th June 2019 @ 4:16pm