Found both! I checked Lane Co., OR and Clark Co., WA GenWeb sites and each had a search engine for cemetery burials. Clark Co. turned out to be the one. They're buried in Park Hill Cemetery in Vancouver.
This is from http://www.rootsweb.com/~waclacem/ParkHill/ph_k.pdf
P 90-4A KARSTETTER Edith M. Karstetter, 1906 - 1967 (s/s George W. Karstetter, b: KY, d: 28 Apr 1967
age 60 yrs 10 mos of heart, int: 2 May 1967, lot owner: self, fd: VFC)
P KARSTETTER George W. Karstetter, 1893 - 19-__ (s/s Edith M.)
You can replicate the search by going to http://www.rootsweb.com/~waclacem/
. Scroll down the page to the search area and put Karstetter there. That will turn up both of them.
Good luck with your search!