They are the Rev. Frank Allen, 54, rector of St. David's Episcopal Church in Wayne, Pa.; his wife Amy, 54; and their sons: Will, 24; Rob, 21; and Ben, 19.
Ben Allen is a student at Duke, in Durham, N.C., and the other family members are alumni, according to Michael Penn, a spokesman for the Duke Alumni Association.
The small sightseeing plane crashed into the side of a mountain near the town of Petersburg on Tuesday.
Amy and Ben Allen were seriously hurt and flown to Harborview Medical Center in Seattle. Amy Allen was listed in serious condition in the intensive care unit and her son was in satisfactory condition, hospital spokeswoman Susan Gregg said. Responders have said one of the two had a broken back and the other a broken leg, but Gregg declined to say what the injuries are.
Another passenger, Thomas L. Rising, 66, of Santa Fe, N.M., was killed.
The pilot of the Pacific Wings de Havilland Canada DHC-2 Beaver also survived with minor injuries and was being interviewed by the National Transportation Safety Board, which is investigating the crash of the single-engine floatplane.
A Coast Guard helicopter crew rescued the survivors from the 1,000-foot level of the steep, wooded mountain the night of the crash. Rising's body was recovered from the wreckage Wednesday night.
"Rev. Allen has conveyed to us his deep gratitude to the U.S. Coast Guard rescue team and to the hospital and community of Petersburg, Alaska, where they were first received and treated with heartwarming care and concern," St. David's spokeswoman Eileen Violini said Thursday in a statement. "Our community's prayers, and the prayers of the Allen family, continue to be with the family of Thomas Rising."
The family is not giving interviews, she added.
The six passengers were part of an expedition run by Lindblad Expeditions, a travel company that offers the eight-day cruise aboard the 62-passenger Sea Bird in an alliance with National Geographic.
The Allens were among 27 people on the cruise as part of Duke's alumni travel program, Penn said.
Given the location of the wreckage, it is amazing that the Allens survived and were rescued quickly, Penn said.
"It is a miracle," he said.