In California, there is no state-level estate or inheritance tax. If you are a California resident, you do not need to worry about paying an inheritance tax on the money you inherit. The inheritance could be taxable in another state, however if it is from Oregon, that state doesn't have an inheritance tax either, so it sounds like good news for you!
*If
If the gross estate of an Oregon resident has a value of more than $1 million, the personal representative or executor of the estate must file a state estate tax return. (Smaller estates won't need to file a return.) Your gross estate will include just about all of the property you own at your death:
the amount is greater than 1.0 million, it would be subject to an estate tax in Oregon.