Good evening Ping. I am gathering from your question that you are interested in purchasing a Distressed property during the auction process. When a bank forecloses on a home, they hold a public "auction" on the court house steps of each county. If you are looking at 97229 it will likely be Washington County in Hillsboro, Oregon.
To purchase a home at this time you must come prepared with a cashiers check for the full amount you are paying for the home e.g. $200,0000. The lender who is foreclosing will have set a minimum bid and have their representative at the auction. If no one bids over the minimum owed to the bank, then the home will revert back to the lender and they will prepare to list the home for sale with an agent, as a Bank owned property. These auctions are listed in various newspapers, with the county and most Realtors can provide the information.
If you are not specifically looking to pay cash up front for a property with no inspection or recourse, but rather are looking for a bargain, then I would suggest finding a highly motivated Realtor that you can trust to provide the exhaustive search for a great deal and be prepared to act quickly. There are a lot of buyers out there looking for the same thing and we often see multiple bid situations for the "deals". There was just one for a home in the Cedar Mill area this past week. Lots of opportunity, but top notch representation is key.