The plane was fully engulfed in flames when emergency responders arrived late Friday at the site about 2 miles from the Canyonlands Field airport, and there were no survivors, Grand County Sheriff James Nyland said.
The victims included the director of a company with dermatology clinics in three states and staff members.
Nyland said the plane had taken off from the airport, about 18 miles northwest of Moab.
Lt. Steve White told KCYN radio in Moab that the plane "pancaked" and skidded along the ground.
The airplane was a King Air A-100, said Mike Fergus, a spokesman for the Federal Aviation Administration in Seattle. He said that "to the best of our knowledge" no flight plan had been filed for the trip, but he said that isn't unusual.
Representatives of the National Transportation Safety Board and the FAA were expected at the scene Saturday, officials said.
Nyland said the victims were the director of Red Canyon Aesthetics & Medical Spa, a dermatology clinic headquartered in Cedar City, his clinic staff and the pilot.
He identified them as pilot David White; Dr. Lansing Ellsworth; David Goddard; Mandy Johnson; Marcie Tillery, 29; Valerie Imlay, 52; Keith Shumway, 29; Dallon Ellsworth, 24; Camie Vigil, 25; and Cecilee Goddard, 25.
Lansing Ellsworth had recently started a monthly skin clinic in Moab, Nyland said. Red Canyon Aesthetics has seven clinics in Utah, two in Nevada and one in Page, Arizona, according to the company's Web site.
The airplane was owned by Leavitt Group Wings, part of the Cedar City-based Leavitt Group, an insurance brokerage. The dermatology group had a time-share agreement with Leavitt Group for use of the plane, said chief executive officer Dane Leavitt.
The group's clinics focused on preventing and treating skin cancer in smaller communities that might otherwise go without care, Leavitt said. "I'm sure the tragedy of this circumstance will hit all of those communities," he said.
He said they left Cedar City on Friday morning to spend the day at their clinic in Moab, and were likely starting their return flight when the plane crashed.
The pilot was an employee of Leavitt Group Wings, Leavitt said.
Moab is about 245 miles southeast of Salt Lake City.