The 12ft high stainless steel structure was spotted in remote backcountry by a state employee counting sheep from a helicopter.
Art experts had speculated that the object resembled the “free-standing plank structures” of the late artist John McCracken.
Mr McCracken lived in New Mexico before his death and his work is represented by the David Zwirner Gallery.
Mr Zwirner said he initially believed it was “definitely” a secret piece by Mr McCracken before ruling it out.
"While this is not a work by the late American artist John McCracken, we suspect it is a work by a fellow artist paying homage to McCracken,” Mr Zwirner told the Art Newspaper.
Watch: Metal monolith discovered in Utah sparks mystery
Lieutenant Nick Street of the state’s Department of Public Safety said that they believed “it’s somebody’s art installation, or an attempt at that.”
He said that the monolith had “human-made rivets” and was buried into the rock to an unknown depth.
“Somebody took the time to use some type of concrete-cutting tool or something to really dig down, almost in the exact shape of the object, and embed it really well,” he said.
“It’s odd. There are roads close by, but to haul the materials to cut into the rock, and haul the metal, which is taller than 12 feet in sections — to do all that in that remote spot is definitely interesting.”
Lieutenant Street admitted that authorities had no idea how long it had been in the location.
“For all we know it’s been installed since the 1940s and 1950s,” he said.
Officials have not given details of the monolith’s exact location amid fears that visitors could become stuck and need rescuing.
“It is illegal to install structures or art without authorisation on federally managed public lands, no matter what planet you’re from,” the department said in a statement.