Hi John,
I don't know how you would find out who the spouse was since the marriage was in 1904 and the Oregon Marriage Database on ancestry.com starts in 1909 or is it 1906?? My suggestion would be to contact a volunteer with Random Acts of Genealogical Kindness for Umatiila County and see if they could look up the marriage for you. Then you would know if she was indeed married in Umatilla County and who the spouse was. And since you have the exact date of the marriage, it would be an easy lookup.
Good Luck and let me know when you find what you're looking for on Lucy.
Lois