Stevens, who won her first election in 1992, is in her fourth term in the Senate after serving two terms in the House of Representatives.
After 20 years in office, the 73-year-old said she's ready to spend more time with her husband, two sons and six grandchildren.
"I am honored to have had the opportunity to represent the citizens of the 39th District," she said in a statement. "Two decades in the Legislature has given me the opportunity to work with many wonderful people and to be their voice when they needed help navigating the burdensome morass of government regulations."
">Rep. Kirk Pearson, R-Monroe, announced Thursday he will run for her seat in the 39th Legislative District, which includes Arlington, Monroe and Sultan plus rural areas of eastern Whatcom and Skagit counties.
The six-term representative said serving in the Senate would be a "great opportunity" to do more for the district.
Stevens' decision was not a total surprise as she said late last year she was evaluating her political future. She had not raised any money for a re-election campaign.
The news did catch friends and political allies off-guard Thursday as they shared what her absence will mean.
"I would call her maybe the most genuine, uncompromising conservative I've ever known," said Larry Stickney of Arlington, a longtime friend who worked with Stevens on several campaigns including the attempt in 2009 to repeal a law expanding rights of same-sex couples. "I consider her a great friend and a great ally. I never saw her betray the cause. She will be greatly missed."
Stevens, the ranking Republican on the Senate Human Services and Corrections Committee, focused much of her legislating energy on improving the way the state deals with children and helps strengthen families.
Early in her career, she battled, often publicly, against the state's Child Protective Services agency. In 1996, she pushed a bill to strip it of its power to investigate allegations of abuse after its involvement in a case in Wenatchee where two dozen people were wrongly accused by authorities of being part of an alleged child sex ring.
"They are leaving children in homes where they should be taken and taking them from homes where they should be left," said Stevens, then a state representative, at a public hearing covered by the Associated Press.
In the past few years, she's endorsed greater use of research in reshaping the policies and practices of Department of Social and Health Services, one of Washington's largest agencies.
"She's been instrumental" in fomenting a transition how the state serves its children, said Sen. Jim Hargrove, D-Hoquiam, who is the committee chairman.
This year, Stevens joined Democratic senators to help pass a bushel of bills to combat human trafficking, most of which Gov. Chris Gregoire signed Thursday.
But Stevens' lasting legacy will be her unending fight against what she often termed the "homosexual agenda."
She stood among the legislative leaders in 1998 that pushed through the state's Defense of Marriage Act defining marriage as a legal union between one man and one woman.
In 2009, she helped raise money and gather signatures on petitions for Referendum 71 to repeal the law granting same-sex couples the same rights under state law as married couples. And not surprisingly, she voted against this year's bill making it legal for same-sex couples to marry.
"Will there be another bill next year, and another the year after that, until homosexuality is taught as normal and only an 'alternative' in Washington's public schools, or some other societal tradition is discarded in the name of 'equality'?" she said. "It is the proverbial slippery slope -- one Washington has been sliding down every time we expanded rights for homosexual couples."
Stevens' didn't intend to say anything about her future until the special session concluded.
But she did tell Pearson. As a courtesy, he has been waiting for her to make her plans public. He said he asked her this week if he could go forward because he wanted to let supporters know at several upcoming Republican Party events.
"She told me it was OK," Pearson said today. "I think it's a great opportunity. I think I can represent my district well in that position."
Pearson, 53, is the ranking Republican on the House Public Safety and Emergency Preparedness Committee. He also serves on the Capital Budget and the Environment committees.
"I think Kirk will fill her seat well and he will adhere to some of the policies she worked hard to accomplish," said Jim Donner of Warm Beach, who represents Snohomish County on the executive committee of the state Republican Party.
So far one Democrat, Eleanor Walter, has formed a committee to seek the office.
Formal filing for state offices is in May.
Jerry Cornfield: 360-352-8623; email@example.com
More Local News Headlines
Another storm bringing strong winds, heavy rain Tuesday 4:11 p.m. Claim filed for PUD worker who says he was retaliated against Food banks serve same number of people, but money doesn’t go as far Be sure your mushroom harvest isn't poisonous Everett council takes up $324.8M budget, which has ‘safe streets’ money Super Kid Emma VanderWeyst interested in pursuing politics, history Edmonds’ Civic Field to become city park Front Porch: Survivor Day planned
Our new comment system is not supported in IE 7. Please upgrade your browser here.