The Fish and Wildlife Service said in Tuesday's announcement that the extension is allowed "when there is substantial scientific disagreement regarding the sufficiency or accuracy of the available data relevant to the decision at issue."
There had already been one extension of the comment period. The new deadline for a final rule will be Aug. 4, 2014.
Wolverines, famous for their wandering ways and ability to survive tough conditions, were eradicated from the lower 48 states by about 1920. Since then, animals from Canada have moved into Montana, Idaho, Wyoming and Washington state. Colorado and California each now have one male wolverine resident.
"We have never had documentation of a breeding pair in Utah, but we definitely see transient males just passing through," Bill Bates, wildlife section chief of the Utah Division of Wildlife Resources, previously told The Salt Lake Tribune.
"We have wolverine sightings reported almost every year in the same locations, and it is consistent enough to have me believe that, even if they are not verified, that there is probably something there."
Recent confirmed sightings in Utah came in 2003 near Morgan and in the Bear River ranges near Logan in 2005.