I know people who still farm this area and may acquire some information.
I believe it was built by a professional builder and can tell from the chimney style and construction it probably dates from the 1950's.
There are many fields in Southeast Wyoming and the High Plains that have been abandoned or planted to grass. It is hard to keep farming wheat in this area of marginal rainfall and high probability of hailstorms. Looking at the surrounding terrain, this field is slightly elevated and surroundings are eroded. Some scraping may have been done.
I think this is on the access road to Hawks Springs Reservoir State Park. Hawk Springs is a little (somewhat abandoned) town a few miles up the highway.