Investigators tell ABC 4 News that controllers lost contact with the pilot just after take-off, after he had turned around and started to head back towards the airport.
Search teams started looking for the plane Thursday night, but couldn't find any signs of it, and continued Friday morning.
Later Friday morning, crews were able to locate the origin of the plane's radio beacon in a remote area in rugged terrain just northeast of Mountain Green.
Officials say a man and a woman were on board the Cessna 210 aircraft, headed to Wyoming.
The pilot lived in the Douglas, Wyoming area and had donated his time to help families in need.
ABC 4 later learned the the pilot and passenger were identified as Daleray Madewell and Jeniffer Sebesta, of Douglas, Wyoming.
Sebesta was 36 years old and worked as a labor and delivery nurse at Memorial Hospital of Converse County.
Stay tuned to ABC 4 News and ABC4.com for more on this story.