Her husband of more than 50 years, Egon Walters, told Eyewitness News he last saw his wife when he got up to take a sleeping pill. When he awoke a few hours later, she was gone.
Walters is said to have walked out in her pajamas and slippers.
Orange County sheriff's deputies are using search dogs to scour Wood Canyons Wilderness Park and the canyons near the couple's home. On Wednesday, the nearly 100-degree heat hampered the search. Some deputies suffered from heat exhaustion, and according to Sheriff's spokesman Jim Amormino, high temperatures reduce the effectiveness of tracking dogs.
Walters has two adult children and one grandchild. Her family said they are very concerned for her well being. Her husband says his wife does not suffer from dementia, but she does have high blood pressure.
He made a plea on Eyewitness News for his wife to come home: "We want to know where you are please, and we're all sorry for what we did to you." Mr. Walters said, referring to an argument he had with his wife the previous night. He also denied causing her any harm or being involved in her disappearance.
Mr. Walters said his wife left without her purse, keys, and shoes. She is not believed to have a telephone or money.
Margot Walters is described as 5 feet 6 inches tall and 130 pounds, with brown hair and gray eyes.
Anyone with information on her whereabouts is urged to call Orange County sheriff's deputies at (714) 628-7170.