Eight passengers and a pilot were on board the flight.
Alaska State Troopers identified the victims as: Rowland Cheney, 71, and Mary Doucette, 59, both of Lodi, California; Glenda Cambiaso, 31, and Hugo Cambiaso, 65, both of North Potomac, Maryland; June Kranenburg, 73, and Leonard Kranenburg, 63, both of Medford, Oregon; Margie Apodaca, 63, and Raymond Apodaca, 70, both of Sparks, Nevada; and the pilot, Bryan Krill, 64, of Hope, Idaho.
Troopers originally gave an incorrect first name for Rowland Cheney.
The DeHavilland DHC-3T Otter, a floatplane, crashed in steep, mountainous terrain about 25 miles northeast of Ketchikan on Thursday.
Authorities haven't determined why it went down.
The plane was on a shore excursion from a cruise ship, sold through Holland America Line. A private helicopter pilot reported seeing the plane's wreckage against a granite rock face, 800 feet above Ella Lake.
"We are incredibly distressed by this situation, and our thoughts and prayers are with those on board the plane and their families," Holland America said.
The eight passengers were from the MS Westerdam, which left Seattle on Saturday for a seven-day round-trip cruise.
The plane had taken off on a tour of the 2-million-acre Misty Fjords National Monument, accessible only by floatplanes or boats.
"Towering granite cliffs, 1,000-foot waterfalls, lush and remote valleys and serene crystalline lakes make up this incredible landscape," the airline says on its website
"There is nothing I can say that can alleviate the pain and overwhelming sense of loss that we and the loved ones of those affected are feeling," said Marcus Sessoms, Promech Air's president. "At this moment, all of us share the pain and anguish of this terrible event."