First, see if there is a property line cleanout. The City of Molalla can assist you with this, call 503-829-6855 (after hours emergency 503-793-9043).
Second, look to see if every fixture; sink, faucet, and toilet is backed up. If it is just a few, you should call a plumber to assist in clearing the blockage.
Third, if it’s every fixture you should step outside and see if you have a “cleanout” which will be a 4” round pipe sticking up a few inches above the grass, either near the foundation of your house (a private cleanout), or up by a nearby city street (property line cleanout). If you cannot find one, you should call a plumber to assist in clearing the blockage.
Fourth, if you do find a cleanout at the foundation of your house you can call a plumber to help you clear the blockage and determine if the pipe was just clogged, or whether it has a more significant defect, like a collapse or offset-joint. If it does have a significant defect, ask the plumber to provide you with a CCTV inspection of the pipe – if the problem turns out to be past the property line in the public street, you may be eligible for re-imbursement from the city for the problem.