Assuming the property was not your principal residence, your realized gain will be subject to OR income tax. You will need to file a non-resident return (Form 40N at http://egov.oregon.gov/DOR/PERTAX/docs/2004Forms/101-045-04PY.pdf) reporting the OR source gain and pay OR income tax. You are required to file an OR return if your OR source income exceeds $1,720 if single or $3,445 if MFJ. Tax rates range from 5% to 9% on taxable income. Since TN does not have an income tax on capital gains (yet), no reporting is necessary for TN tax purposes.
The gain on the sale of the property is calculated as the difference between your net sales price and your cost basis (adjusted for improvements and depreciation).
Your net sales price is the contract selling price less any selling costs (i.e. broker commissions and other transaction costs as well as fix-up expenses if real property is involved).
Your cost basis is determined by taking your original purchase price (plus any non-recurring closing costs) and adding the cost of any improvements made during ownership and then subtracting any allowable depreciation (whether claimed or not). If you inherited the property you would claim as your acquisition cost the value for the asset claimed in the decedents estate tax return. If no estate tax return was filed then you use the fair market value of the asset (supported by an appraisal if not readily determinable) as of the date of death. Identifying all your improvements and other items that add to your cost basis is one way of reducing the ultimate tax impact.
For Federal purposes if you own the property for more then one year, then the gain will be treated as a long-term gain and will be taxed up to a maximum capital gain rate of 15% (5% if the gain would otherwise be taxable in the 10% and 15% brackets). Otherwise the gain is treated as a short-term capital gain and to the extent not offset by other capital losses will be considered as ordinary income the same as wages and interest subject to whatever your marginal tax rate is. OR makes no distinction between ordinary income and capital gains, it is all taxed at the same rate (i.e. from 5% to 9%).
Assuming the $225,000 is all taxable gain and that you have no other OR source income, your OR tax would be about $18,000 to $21,000 depdening on available deductions, your filing status, etc.
Because it is impossible for me to identify and consider ALL the relevant facts, this advice is not intended or written to be used for the purpose of avoiding penalties, and cannot be used for that purpose.