There is a rebuttable presumption of equal contribution in Oregon divorces.
This means that, regardless of how property is titled (separately, jointly, jointly with right of survivorship, etc), assets which are acquired during marriage are rebuttably presumed to have been acquired by the efforts of both husband and wife.
As such, these assets are subject to division (usually equal division) between husband and wife if the couple divorces, even if the assets are separately titled. In other words, it generally does not matter if a bank account is held in the name of only spouse, or if a car or a piece of real estate is titled in the name of only one spouse.
This is true regardless who earned the money that was used to buy the asset. Even if one spouse earned no money at all during the marriage, the earnings of the other spouse are presumed to be in part dependant on the supportive environment provided by the non-earning spouse.
This is a rebuttable presumption. This means that if the earning spouse can prove that the other spouse did not provide a supportive environment, including for example emotional support, homemaking or child care services, and the like, then theoretically the presumption of equal contribution can be rebutted.
It is very difficult to rebut this presumption in actual fact, however. Only the most extreme cases are likely to produce a ruling from a court rebutting this presumption.
The one area where this presumption does not apply is where the asset in question was inherited or received as a gift, and not co-mingled with other assets of the family. This situation is explained in somewhat more detail in another posting titled Divorce and Inherited Property.