Thomas Locker was born in New York City in 1937. In the 1960s, he began his career as a landscape painter. In 1982, he decided to try his hand at writing and illustrating children's books. His first, Where the River Begins, was named one of the 10 best illustrated children's books of 1984 in the New York Times Book Review. During his lifetime, he illustrated more than 30 children and young adult books, several of which he also wrote. Some of his works include John Muir: America's Naturalist, Anna and the Bagpiper, The Ice Horse, and The Man who Paints Nature. The books he worked on have received numerous awards including the Christopher Award, the John Burroughs Award, and the New York Times Award for best illustration. He died on March 9, 2012 at the age of 74.