I’ve only seen them twice; once in the movie “Jeepers Creepers”, and just recently in the prairies… both look old and are in rural areas. I had assumed the one in the movie was just invented for the script and not found in reality, but I spotted a real one and want to know what they are.
They are corrogated metal, larger diameter (2-4 feet), and appear to be access chutes to underground rooms of some sort. Their steepness however seems to rule out human access, their distance from any structure seems to rule out being connected to a normal basement, and their being open and very large seems to rule out their being ventilation pipes for root cellars.
I’m sure there is a simple explanation of what these are used for - a couple pictures here: