She is also a former war correspondent who filed reports from foxholes at Korea's infamous Pork Chop Hill and is co-author of investigative books about the controversial deaths of Marilyn Monroe and legendary Russian "mad monk" Grigori Rasputin.
It's a quest some believe is as fanciful as the legend surrounding the artifacts -- but Barham is having none of that.
The diamonds, Faberge eggs, imperial Russian crowns and tiaras, jewel-encrusted gold picture frames and opera-length strands of pearls, rubies, sapphires and diamonds are hidden in seven coffins in a hole 7 feet square and 10 feet deep in the middle of Mongolia's Gobi Desert, she contends.
That's where Barham says her stepfather buried them on Oct. 3, 1917.
Onetime Russian prince George Meskhi-Gleboff spoke often of the treasure after he came to the United States and married Barham's mother, socialite and silver heiress Jessica Gorman Barham.
Shortly before his death in 1960, Barham says, her stepfather handed her a sealed envelope containing a map that showed exactly where the treasure was hidden. Embittered to the end by the Russian royal family's execution, he asked that she not do anything until the Russian government admitted to the slayings of the Romanovs and recognized them with a state funeral. That occurred in 1998.
But soon after, the hand-drawn map mysteriously disappeared. Although Barham has searched her nine-bedroom, 10,000-square-foot mansion for it without success, she insists she has memorized the jewels' hiding spot. Now, the energetic dowager is determined to see the trove recovered.
"They should be returned to the Russian people," Barham says of the czar's treasure.
There are those who doubt that these priceless jewels still exist and whether Barham has any shot of finding them if they do. Some experts on Russian history, while praising Barham's passion for the project, question whether she has all her facts right. A few years ago, she tried to get the Discovery Channel interested in partnering with her to search. But the deal fell through when she could not produce the map.
Pointing to a copy of a circa-1916 map of Mongolia, she is certain she can find the treasure.
"It's there," she says.
Barham is a petite woman who carefully guards her age. But she readily talks of growing up amid wealth as the daughter of the late Frank Barham, onetime publisher of the L.A. Herald-Express and business partner of newspaper mogul Hearst.
Her family's close relationship with the powerful Hearst meant they were frequent guests at San Simeon and at a second Julia Morgan-designed Hearst retreat, Wyntoon, near Mt. Shasta.
In the late 1940s, Barham worked as a reporter for the Herald-Express. Hearst himself sent her to Korea in 1951 to report on the war there. Later, she wrote for Hearst's successor paper, the Herald-Examiner.
After Gleboff married her mother, Barham says, she often heard him recount how had he had been an aide to Russian Czar Nicholas II and his wife, Czarina Alexandra, at the time of the Russian Revolution.
Gleboff served as assistant to the treasurer of the "czar's purse." In that role, he was summoned on Feb. 28, 1917, to the czar's palace south of St. Petersburg and instructed by Alexandra to transport the Romanovs' personal treasures to the Bank of China in Peking, now known as Beijing.
The valuables were hidden in seven coffins, two of which held the bodies of children being taken to China for burial as a ruse to explain the trip to authorities, Gleboff recorded in his journal. He and his traveling party set out first by train and then by camel caravan for China.