When you enter your 1099-R in your Federal return, be sure to enter an amount for State Distribution and State Tax Withheld in Boxes 14 and 16.
This in the Wages & Income section, under Retirement Plans and Social Security > IRA, 401K, Pension Plan Withdrawals.
This will then flow into your Oregon return. Here's more info from Oregon Dept. of Revenue.
@user6141620