I think this odd-shaped device has been sitting in a field at Emandal for a fair while, but in several years of visits I'd never gone over to see what it was. This year I did.
It turns out to be a Plate Boundary Observation Station -- one of over a thousand fixed points on the continental US that are repeatedly measured from a fixed position in space. Modern GPS technology is accurate to within an eighth of an inch and minute changes in distance between stations tell us how and in what direction the tectonic plates that make up this part of the globe are moving.
As a handy notice board pinned to the side of the station tells you, the station's a part of the National Science Foundation-supported EarthScope project, which aims to help us better understand the geological structure of the North American continent.
You can get updates on what the observatories are telling us at the Plate Boundary Observatory homepage. One of the things it has enabled is the wonderfully-named SNARF, which stands for Stable North American Reference Frame. It's a common framework that researchers can use to more accurately combine data from projects on different parts of the continental plates.