Washington state has some options when it comes to PTA schools, as there are 6 PTA programs accredited by the CAPTE in the state.
You might also consider related programs - occupational therapy tends to be a commonly selected one. Responsibilities and training is closely related to physical therapy.
Below are listings of all the schools we could find that offer physical therapy assisting (or related) programs. Simply browse the listings and click on one of the buttons to get more information about the specific program to see if it's right for you.