Hi Kristine,
Was their marriage info listed in their obituaries?

If not, you'll need a copy of their marriage license. Lewis E. Hogan married Anna/Annie/Annabel about 1893. One of his stories said he was fighting outlaws in 1895 in Checotah, Oklahoma. That's where I'd look for their marriage info. However, I'm not familiar with where those records are kept in Oklahoma. If you don't know, you can look up the county on Rootsweb.com, Home, about half way down the page on the left-hand side. There's city/state converter to county.

Anna/Annie/Annabel's maiden name should be listed on one of the children's birth certificates.

Her maiden name will be on her death certificate if the person reporting to the County knew her maiden name. You already have her name as Anna B. Sarber on your family tree so I'm confused when you say you don't know it.

The Gem County Clerk-Auditor-Recorder, co.gem.id.us/clerk-auditor-recorder/default.htm has copies of death certificates and there is a fee. Successful Searching!