In both Oregon and Washington, creditors can typically garnish a bank account to collect a debt only after obtaining a judgment. Once a creditor does obtain a judgment, it may file a non-wage garnishment affidavit upon any of your banks. After the bank is served, the bank may be obligated to pay the judgment creditor any money that you have on deposit up to the amount needed to satisfy the judgment.
A bank garnishment is far worse that a payroll garnishment in the sense that the creditor is not limited to a percentage of available funds. Unfortunately, many debtors in both Oregon and Washington only learn this through bitter experience.
If you do owe money on a judgment, depositing money into an account is a risky proposition. Until you do file bankruptcy, you may want to seriously consider using a check cashing service until your case is filed. Given that there are severe limitations in states like Oregon on the amount of money that can be shown in a bank account at the time of filing, relying on cash and money orders to pay your bills in the month or so before your case is filed may aid you in getting your bankruptcy filed as quickly as possible.