You said you lived in Washington and California, but you didn't say where you worked.
In general all of your income is subject to tax by the state you lived in when you received the income, no matter where the income is from. Any income that you earn for work that you do in a state that you do not live in is subject to tax by the state that you worked in. The location of your employer's headquarters doesn't matter. What matters is where you live and where you did the work.
If these rules result in the same income being taxable by two states, one state will give you credit for part or all of the tax that you pay to the other state. Usually the state you live in gives you credit for tax that you pay to another state that you worked in, but California and Oregon are among the few states that are exceptions to that usual rule. If you live in California and work in Oregon, Oregon will give you credit for tax that you paid to California.
If you lived in Washington for part of the year and in California for part of the year you are a part-year resident of both states. You will have to file a part-year resident tax return for California, and allocate your income based on how long you lived in each state.
