Marjorie Knuckles' body was discovered Sunday, WSPA-TV, Spartanburg, S.C., reported.
She had been reported missing by a relative who was last in contact with her on Jan. 30. Police received the call that her body had been found Sunday morning.
The cause of death has yet to be determined.
Officers investigating Knuckles' death said they are looking for her adopted son Brandon Scott Knuckles, who is considered a person of interest in the case. Marjorie Knuckles adopted Brandon when he was a young boy. He is now 45 years old and described as 5-foot-11 and weighing 200 pounds.
Police said Marjorie Knuckles' blue 2004 Nissan Maxima was also discovered to be missing.