Her corpse was discovered near Lake Don Pedro, about halfway between El Portal, where the sightseers were last seen, and Sierra Village, where two bodies were found in the trunk of the women's torched rental car.
The charred body of Julie's mother, 44 year-old Carole Sund, was one of the two in the vehicle, and the first to be identified.
Mrs. Sund, her daughter, and 16 year-old Silvina Pelloso, a family friend from Argentina, began their trip Feb. 12, when they left the Sund's home in the Northern Californian coastal town of Eureka.
They were last seen alive Feb. 15, eating at the Cedar Lodge restaurant in El Portal, a remote town just outside the western gate of the park.
The torched shell of the car the trio had rented for their trip was found last week on a wooded hill in Sierra Village, about 100 yards off Route 108, also known as Sonora Pass, nearly a three-hour drive north of El Portal.
With dental records, investigators were able to identify one of the two badly burnt bodies found in the trunk as Mrs. Sund. The FBI said Friday that the second body is likely that of Silvina Pelloso.
Authorities say they will do everything possible to catch the women's killer. "We will bring all available resources to bear to solve this horrible crime," said FBI agent James Maddock. "We are all committed to solving this crime and bringing those responsible to justice."
The discovery of the rental car generated several new reports of possible last sightings. But authorities are trying to sift through the accounts to determine their credibility.
Maddock would not comment on how Julie Sund or the other sightseers died, or what lead investigators to her body. But he says investigators continue to identify and eliminate suspects.
Before Friday's announcement, relatives of the victims said they would welcome any information that would help crack the case and bring those responsible to justice. "We're hopeful this recent development will help investigators solve this case," said Silvina's mother, Raquel Pelosso.