Authorities say a body discovered in Wyoming is believed to be Gabrielle “Gabby” Petito.
The FBI said the body was found by law enforcement agents who had spent the past two days searching campgrounds.
The cause of death not yet been determined, said FBI Supervisory Special Agent Charles Jones.
Mr Jones said investigators are still seeking information from anyone who may have seen Ms Petito or Brian Laundrie around some camping sites located on the park’s eastern boundary, the same site that was the subject of a law enforcement search efforts over the weekend.
Ms Petito and her boyfriend left in July on a cross-country trek in a converted van to visit national parks in the US West.
Police said Mr Laundrie was alone when he drove the van back to his parents’ home in North Port, Florida, on September 1.
Mr Laundrie has been identified as a person of interest in the case. He was last seen on Tuesday by family members in Florida, and investigators have been searching for him for the past two days in a 24,000-acre wildlife reserve near Sarasota, Florida.