This image is located in Windsor, Colorado(40.4526°N -104.9273°W) and it continues to puzzle me. There is a high fence surrounding the about 5 acre area. I looked up who the land is owned by and the town of Windsor currrently owns it, however is it possible to be a ex-military complex of some kind? I thought this because of the American flag on what looks like a launch pad
Windsor, Colorado is an area with a very active oil and gas exploration industry, so like @PainFither, my guess would be that this is a pad being built in preparation for use as an oil or natural gas storage or drilling facility.
The Colorado oil and gas commission requires that oil and gas facilities be surrounded by fairly high fences to prevent innocent people or large animals from wandering into them and being hurt.
Windsor is not very near to any plausible military facilities that would need that kind of pad, and is certainly not a spacecraft or missile launch site (something that is virtually impossible to keep secret because launches are visually spectacular and visible from long distances over the front range plains that surround it).
It seems to be a construction site. Possibly, a foundation for a storage tank.