Retirement tax questions

No letters were sent to me or my kids. We had no idea the IRA even existed until Stifel called me to tell me they had returned the funds to Oregon (they were still in the form of shares at that time, until Oregon decided to cash it out) and Stifel told me the website to go to for the unclaimed property. So I did that, filled out and sent in the paperwork, and now everything is done and they are cutting the checks, one in my son's name because he is over 18 and one in my name on behalf of my daughter since she is under 18. So I don't even know if it's taxable but I certainly don't want to assume and then they get in trouble for not claiming it on a tax return. And the State of Oregon said they can't give me any financial/legal/accountant info on how it will affect our taxes so I'm totally confused and just don't want to make any mistakes with this strange situation. Thank you so much for the help! I wish they could just tell me whether to expect a 1099 or not. Seems like they should at least be able to give me basic info on what I need to do but they said they can't give any info like that because they aren't specialists in taxes.