(CNN)Illustrator Candace Jean Andersen was doing some research for a children's book on orcas when she stumbled into a mystery.
The identity of the lone woman scientist in this 1971 photo was a mystery. Then Twitter cracked the case
In an old article, she discovered a photo of scientists at the 1971 International Conference on the Biology of Whales in Virginia. And she noticed something: Amid the sea of male faces -- 37 of them -- was a lone woman, her face partially obscured.
The article named all the men, but the African-American woman was listed as "not identified."
"Not identified, why? Who is she? What did she contribute to the conference? What's HER story?" Andersen wondered.
She put down her picture book project and started looking.
"It bothered me for days not knowing who this woman was. If she was there, at that conference, she's got to be important. I need to know her," Andersen told CNN.
Finding her seemed like it would be tough.
The picture was more than four decades old. Complicating things even further, the woman was standing behind another marine biologist, so only half of her face was visible.
So Andersen posted the photo on Twitter and asked for help.
She tweeted: "Hey Twitter I'm on a mission: The woman in this photo was an attendee at a 1971 International Conference on Biology of Whales. She is the only woman, & the only one captioned 'not identified' in the article I found the photo in. All the men are named. Can you help me know her?"
Andersen doesn't have a huge Twitter following, so she wasn't expecting much. But the tweet soon caught on and people all over the world joined the search.
After following a few false trails, social media detectives -- with help from an archivist at the Smithsonian -- were able to confirm within days that the woman was Sheila Minor Huff. At the time, she had been a biological specimen analyst at the Fish and Wildlife Service.
As it turns out, Huff went on to have a 35-year scientific career with the federal government and retired 12 years ago as a high-ranking environmental protection specialist.
Andersen tracked Huff down on Facebook and the women talked on the phone for almost an hour.
"She's very sweet. Humble, kind-hearted, positive. She didn't have a negative thing whatsoever to say," Andersen said.
Huff, who's now 71, lives in Virginia. She wasn't aware of the social media search until Andersen contacted her.
"I had to go to open a Twitter account to see what all the fuss was about," she told CNN.
Huff said she never really worried about being identified, or recognized or celebrated, because she is passionate about natural resources and just wanted to get the job done.
"I do consider myself hidden because what's important is the outcome," she said.
Her work took her all over the country and she took on more and more responsibility as she rose t