OLYMPIA, Wash. -

King County Superior Court Judge Mary Yu was appointed to the Washington state Supreme Court on Thursday, and she will be the first openly gay justice, as well as the first Asian-American, to serve on the state's high court.

Yu, who turns 57 next month, was appointed by Gov. Jay Inslee on Thursday. She replaces Justice James Johnson, who announced his retirement last month because of health issues. Johnson's last day on the bench was Wednesday. Yu will be sworn in later this month.

She will be the sixth woman on the current nine-member court and the second ethnic minority. The daughter of immigrants -- her mother is from Mexico and her father is from China -- she's also the first female Hispanic member of the court, and the third of Hispanic descent in court history. Justice Steven Gonzalez was appointed to the court in late 2011, was sworn in in early 2012, and was elected to a full term later that same year.

Yu was appointed to the King County Superior Court by former Gov. Gary Locke, and previous to that, she served as deputy chief of staff to the late King County Prosecutor Norm Maleng. She's the first Supreme Court justice appointed by Inslee, who took office in January 2013. To keep the seat, she will have to run for election in November to serve the rest of Johnson's term, which was set to expire in January 2017.