Does I need to have Guardianship in Oregon before I can move my Mom into an ALF?

I need to move my mother to Portland (that's where I live) and get her into an assisted living facility here. I just acquired guardianship for her in Washington where she now lives. What is the process to transfer guardianship? Do I need a lawyer? How long does it take? Can I move her into an assisted living facility in Portland BEFORE the guardianship transfers from Washington to Oregon? ANY help or advice would be GREATLY appreciated!