Wildlife officials spotted the "unusual" object while counting sheep during a flyover in a remote south-eastern area of the US state.
They said the structure had been planted in the ground between red rock.
There was no indication who installed the monolith, which was about 10 to 12ft (3.6m) tall.
In an interview with local news channel KSLTV, the helicopter pilot, Bret Hutchings, said: "That's been about the strangest thing that I've come across out there in all my years of flying."
