Authorities have been unable to identify one of the seven people killed when a Greyhound bus collided with an out-of-control truck near the Utah-Wyoming border.

The Utah Highway Patrol earlier released the names of six of the seven, but the identity of the seventh remains a mystery.Sgt. Gary Whitney said all efforts to find out who the man was have failed, but the Utah Highway Patrol and state medical examiner's office have not given up.

The unidentified victim, a man about 30, was carrying a discount shopper card from the Sacramento area, but the name on the card apparently wasn't his, Whitney said.

Authorities still are going on the assumption the man likely is from north-central California, he said Thursday.

"They've been checking the area, where they thought he might be from. They faxed down (to Sacramento) copies of his fingerprints, but they couldn't get a match," Whitney said.

The medical examiner next made original prints from the body and those are being sent to Sacramento law enforcement officials in hopes a clearer set of prints may be matched.

The man's fingerprints also are being filed in an automatic fingerprint information system that covers 11 Western states and are sent to the FBI.

"That's not coming up real positive, so right now we're really not too close," Whitney said.

Killed in the Tuesday morning crash on I-80, 10 miles from the Wyoming border were Neddie Hernandez, 41, of Idaho Falls, Idaho, and her 7-year-old daughter, Tina Marie Jones; Lance E. Jolley, 28, Glendale, Wis.; Troy Jenkins, 20, Lebanon, Ore.; Malinda Martin, 19, Afton, Wyo., and Marie E. Yeager, 55, Orem.