The Genealogical Forum of Oregon library, in Portland, has the Oregon Marriage Index on 4 CD's (Vol. 1-4), covering the period from 1925-1945. They also have microfilm of the Oregon Marriage Index from 1946-1960 and 1966-1970. There is a period of 1961-1965 that is missing, but I've been told the Vital Records Department should have the index for 1966-1970 at their office.
I checked the above mentioned periods, both on the CD's and on the microfilm, the listing for the groom, Walter Oliver MOORE. I did not find a marriage for Walter and Effie.
Since the information you have on Effie's obituary said she lived in Lyons, Oregon 18 years (Lyons is in Linn County) and you said she died in 1965 or 1966, that would mean she was in Lyons from about 1947 or 1948. It is possible someone in Linn County, Oregon has done an index for the Linn County marriage records from 1961-1965 from the courthouse records. You might want to leave a message on the Genforum messageboard for that county regarding the marriage of Walter and Effie. If that doesn't work, you might contact the Linn County Courthouse. My reference books say the County Clerk has marriage records.
Sorry I couldn't find the marriage for you. Have you checked the other states you listed, where you found Walter, for Walter's and Effie's marriage (Oklahoma, Colorado, Indiana)?