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

Yu, 57, 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.

"The appointment of a Supreme Court justice is a responsibility I take very, very seriously," Inslee said at a news conference. "Judge Yu has distinguished herself throughout her career."

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.

Inslee said that Yu was "someone of great intellect, dedication, compassion, with a never-wavering commitment to ensure justice for everyone."

As a superior court judge, when the state's first gay marriages started taking place around the state on Dec. 9, 2012, she officiated over the first King County marriage just after midnight.

In 2011, she, along with Gonzalez, received the Outstanding Judge of the Year award from the Washington state Bar Association for their work on researching racial disparity in the state's criminal justice system.

"I believe it's clear to everyone that judge Yu has both the qualifications and the life experience to sit on our state's highest court," he said.

Yu will be taking the seat of the justice who was considered the most conservative member of the court. Johnson often wrote in favor of individual property rights, police tactics and the state's Public Records Act. He was also not afraid to stand alone in dissent. He recently cast the only vote against having the court retain oversight of education spending in Washington, saying the court was overstepping its bounds, and the only vote against allowing the governor's office to claim "executive privilege" in withholding documents from public view.

Johnson, 68, was first elected to the court in 2004 and re-elected in 2010. He decided to not serve out the rest of his term after missing oral arguments because of illness. He told the News Tribune of Tacoma that in addition to needing to have a hip replacement redone, he was diagnosed with polycythemia vera, a rare, but nonfatal, blood disease that causes bone marrow to overproduce cells, especially red blood cells, and that causes headaches and fatigue.

After the ceremony, Johnson told the Northwest News Network that while he personally likes Yu, he was concerned that "this court still is not balanced, does not represent all the people of the state, and I'm not sure this is a positive step."

In her earlier remarks, Yu addressed the potential consternation some may have with the fact that she's from the predominantly liberal city of Seattle.

"While I am from King County, I want each of you to know I am truly and earnestly committed to serving all the people of Washington," she said.

Yu earned her bachelor's degree in religious studies from Rosary College and a master's of theology from Mundelein College of Loyola University. She got her law degree from the University of Notre Dame Law School. Before coming to Washington state, she worked for the Archdiocese of Chicago, first as an associate and later as the director for the office for the ministry of peace and justice.