Oregon has a State Estate Tax
Oregon residents are subject to an estate tax for estates of more than $1 million. This tax falls on the estate of the person who died, the beneficiaries or heirs inherit what's left. There is no inheritance tax in Oregon, this would be tax that falls on the heirs and beneficiaries, not on the estate of the person who died.
This state-specific estate tax is in addtion to the federal estate tax, and that tax also falls on the estate of the person who died, not on the people who inherit that property. There is an exemption of $10 million, which is indexed to inflation and is currently $11,580,000, and only people who die with an estate larger than that exemption will have to pay estate tax, which means that it is estimated that only the richest .14% of Americans will be subject to the estate tax at all, or only 2 out of every 1,000 people who die.
If someone dies in Oregon with less than the exemption amount (currently $11,580,000), their estate doesn't owe any federal estate tax, and if someone dies in Oregon with an estate worth less than $1 million, there is no Oregon estate tax, either. The heirs and beneficiaries inherit the property free of tax, and don't pay income tax on it, either, because inherited property is not ordinary income. The only exception to this are inherited retirement accounts, which are subject to income tax as the assets are withdrawn.
Information about the Oregon estate tax and the forms necessary to file it can be found at Oregon's Department of Revenue website.