Toshiaki Amimoto, 65, and Etoko Amimoto, 60, died after the fall. A 30-year-old man was airlifted to Moab Regional Hospital.
All three were from California, Chief Ranger Scott Brown told The Post.
The cause of the fall is currently unknown, Brown added.
There was some rain and snow at the time of the accident, and temperatures were in the low 30s, the sheriff’s office said.
The Delicate Arch Trail temporarily closed following the accident but reopened later that evening. Park officials tweeted that winter conditions have caused slippery hiking and warned visitors to proceed with caution.
Rangers frequently have to rescue those who underestimate the 3-mile-long, 480-foot climb to see the arch up close, according to the National Park Service.