The cruise ship line Holland America Line said in a statement eight of the nine people on the plane were passengers on the Ms Westerdam, which is on a seven-day round-trip cruise that left Seattle June 20.
The ninth person is the pilot of the plane.
The plane, owned by Promech Air, was operating a shore excursion sold through Holland America Line, the statement said.
"We are incredibly distressed by this situation, and our thoughts and prayers ware with those onboard the plane and their families," the statement said. "Holland America Line is extending its full support to traveling companions of the guests involved."
A spokesman with the Federal Aviation Administration says the DeHavilland DHC-3 Otter crashed Thursday afternoon under unknown circumstances.
Medical responders were headed to the site, and Alaska State Troopers said the condition of those on board wasn't immediately known.
The Coast Guard says it received a report of the overdue turboprop operated by a Ketchikan-based sightseeing company around 2:15 p.m. PT Thursday.
Troopers say an emergency locator transmitter activated near Misty Fjords National Monument, and a helicopter pilot spotted the downed aircraft above Ella Lake, about 1300 kilometres southeast of Anchorage.