Another 246 people were mauled in the United States during that same time period, 1990 to 2011, the group said. The group's website did not have figures for 2012.
In California alone, 14 people were mauled, but Hanson's is just the second death.
In 2007, an escaped Siberian tiger attacked and killed one person and injured two others in a cafe at the San Francisco Zoo
Love of lions started early
Hanson's love for big cats began when she was very young.
"As my mother can tell you, I have had the goals of working with big cats since she adopted a tiger in my name when I was seven," Hanson wrote in a 2011 letter.
While working at a Washington ski resort while in college, she met a little boy who told her his grandparents owned four tigers. She befriended the family.
When she graduated from Western Washington University, her father presented her with a plane ticket to fly to Nukuru, Kenya, with the family and see the work being done with the animals there.
"I will be volunteering at the Cheetah research center, which is run by Project Survival," Hanson wrote in a college graduation letter. "They (also) have a facility in California known as Cathaven. The owners of Cathaven have invited me to see this facility, so I'm hoping to get down there this summer."
In the letter, Hanson thanked her family and friends for helping her get close to her dreams.
"This was her dream come true," her father told CNN affiliate KCPQ. "Working with big cats all day long, nothing but big cats."