Hendrickson is best known for her discovery of the remains of a Tyrannosaurus rex in South Dakota on August 12, 1990, in the Cheyenne River Reservation.
[2] In 1955, Hendrickson was enrolled at Munster's public elementary school, frequently being praised by her teachers as "a good student and obedient child".
[4] A strong swimmer who had once been on her high school's swim team, Hendrickson quickly learned to dive and began collecting tropical fish off the Florida Keys to sell to aquarists and pet stores.
Her job was to retrieve valuable building materials that were stored in a cargo freighter which ran aground on a coral reef.
Although she found the work too monotonous to pursue full-time, writing that "You could dig for months and find nothing in the Dominican caves,"[8] she continued studying paleo entomology, becoming an expert at identifying fossilized insects.
With them, she took part in many diving expeditions, the most notable of which were the Royal Quarters of Cleopatra, and Napoleon Bonaparte's lost fleet from the Battle of the Nile.
In 2001, she published an autobiography entitled Hunt for the Past: My Life as an Explorer (New York, NY: Scholastic, Inc).