Thanks so much for the link to the Topeka Genealogical Society! I checked their surname index, and there is a C.W. Cowan who died in 1898... I'll have to look into that. Very well could be Clark! I'll have to contact them, to see what other information they may have.
I've looked for an obituary for Elizabeth Belle, but have not found one as of yet. I know when and where she died, and have seen the death certificate, but so far no obit. The certificate just lists C.W. Cowan for her father's name, and that both parents were born in Missouri. Mother's name is "Not Known".
Edit: Ooh, and thanks for the 1910 Census info!!!!