SAN FRANCISCO — Judge Betty Fletcher, a pioneering woman on the U.S. Court of Appeals for the Ninth Circuit and a tenacious member of its liberal wing, died Monday evening in Seattle. She was 89.

Fletcher was only the third woman to join the Ninth Circuit when she was confirmed by the Senate in 1979. A prolific author of published opinions, she was a proponent of environmental protection and civil rights and one the court’s most staunch opponents of the death penalty.