You can contact the archives for copies of their death certificates which should list parents names, but this is not free. You can send them an email for more information but you need to be specific in your request, with exact dates of death:
Name: Willis, Mary M County: Hood River Death Date: 1 Jun 1955 Certificate: 6655 Spouse: Lee
Name: Willis, Lee J County: Hood River Death Date: 9 Feb 1952 Certificate: 1448 Spouse: Matilda
Oregon State Archives 800 Summer St NE Salem, OR 97310 503-373-0701 ext. 1 Fax: 503-373-0953 firstname.lastname@example.org
For their obituaries, try posting on the Hood River Rootsweb message board, again, list their dates of death.
I hope this helps with your search. Good Luck! Laura