The 54-year-old Oklahoma Senate District 38 candidate was discovered in his Dodge Ram in Sandy Sanders Wildlife Management Area south of Erick, a day after being reported missing.
The Oklahoma State Bureau of Investigation said crime scene technicians were at the site and the cause of death remains undetermined, with authorities still investigating the circumstances.
Christian, a Republican and one of three candidates for the open seat, will remain on the June 16 ballot despite his death.
Why was an Oklahoma Senate candidate found deceased in his truck inside a remote ravine?
What happened during the Oklahoma politician's final 48 hours before he was found dead?