Hi Joanne, I found a Bertha J. Caskey Estmated Birth Year-1883, died 28 June 1914 Lincoln Co., WA; Her age was 31 years, 8 months, Father's Name-Thomas Boggs and Mother's Name-Elizabeth Kesler. Source: FamilySearch, http://pilot.familysearch.org/recordsearch/http://pilot.familysearch.org/recordsearch/.
I also found a Bertha Caskey buried in Davenport, WA but married to a different person. I'm pursuing this with the person who posted the cemetery index on the Internet. I'll keep you informed.
I can find nothing for Jesse Benjamin Caskey. I'm thinking he left Lincoln Co. after Bertha's death. Successful Searching!