Hi Donna, I saw that your Charles F. Atwood died in 1921 and I went through about half of the cemeteries in Washington County that have been indexed and no Atwood's appeared. That could be because so far only half of the cemeteries in that counties have been indexed.
If he didn't have a permanent marker, the record of his burial might have been miss-placed.
You can contact the Genealogical Society of Washington County Oregon, gswco.org/docs/contact.html and ask if they have indexes of cemeteries.
Wait another year until more cemeteries are indexed & submit a query then.
While searching I found the following info. In 1910 the Atwood family was living in Fondulac, Tazewell Co., Illinois. Frank Atwood, b. IL, 28, marr 7 yrs, factory hand implements. Leta, wife, b. MO, 28. Irene, b. IL, 4. Roy, b. IL, 2.
In 1920 I found an Irene Atwood in Portland District 87, Multnomah Co., Oregon. She was born in IL and 14 and a boarder.
A Frank Atwood died 21 Nov 1921, Washington Co per death certificate 214. Source: Oregon Death Index 1903-98, Ancestry.
You can request a copy of his obituary from Random Acts Genealogical Kindness, raogk.org/oregon3.htm, read guidelines, choose Oregon, choose Multnomah Co and choose one volunteer.
A Roy Atwood died 16 Oct 1934, Wasco Co., Oregon per death cert #157. Spouse-=Alma. Source: Oregon Death Index 1903-98, Ancestry.
You can request a copy of his obituary from RAOGK, choose Wasco County.
An Irene May Shakespeare [someone has entered Irene May Atwood] under the married name b. 1 Aug 1905, Illinois died 23 Aug 1989, Orange Co., California. Mother's Maiden Name=Johnson. Father=Atwood. Source: California Death Index 1940-97, Ancestry.
I'm not familiar with that county but I'd check if RAOGK has a volunteer there too. Successful Searching!