I am not a relative. I searched ND online death index
https://secure.apps.state.nd.us/doh/certificates/deathCertSe...

These two must be them. You should track down obits.
PITZER, FRANK, died 03/05/1959 in Morton County ND, MALE, age 75 Years, born 05/18/1883, resided in Morton County ND

PITZER, ANNA, died 07/08/1961 in Burleigh County ND, FEMALE, age 66 Years, born 05/28/1895, resided in Morton County ND

I might have found Anna's lineage.
http://worldconnect.rootsweb.ancestry.com/cgi-bin/igm.cgi?op...

Just in case worldconnect disappears and this message board remains...I with leave a genealogy trail behind.
Note: 1900 Minnesota Census, p. 6A: Anna F. (6) is listed as livi ng with her parents in Trondhjem Twp., Otter Tail Co.
Father: Haaken Pedersen OUREN b: Jun 1865 in Østre Totens Parish, Oppland, Norway
Mother: Hannah HAGEN b: Jan 1866 in Norway

Michael Andrews, USGenWeb Volunteer
http://www.usgenweb.org