You might think this is an easy question to answer. But it’s not!
Oregon Vital Records needs to know in which county the license was issued. So, in Oregon, if you want to know if someone is married, you might need to check county by county.
It’s no better in Washington State. You would need to know the approximate date of marriage and the county in which it occurred. Otherwise, you have to search county by county.
Is this good or bad, or a little of both? It’s bad if you really need to know if someone is married or if you can’t remember where you got your marriage license and now need a copy of it.
It’s good if you are a polygamist (at least one smart enough not to get married each time in the same county and state!). It’s also good in another way. IF there was One Big Database that had all this information (the same way people think criminal records are stored, e.g. see here and here), you’d have an even bigger problem on your hands than that elusive marriage license. Think Nineteen Eighty Four? Or, EPIC?