I am forwarding a copy of this posting to Lee Adams. Lee is the current sheriff of Sierra County and is an avid historian and genealogist. His department may have information about previous sheriffs. (I assume from your post that Samuel was the Sheriff of Sierra County.) You may also want to check with the California State Sheriff's Association. They were established in the late 1890s and may have information as well. Their office is in West Sacramento and their web site is at: http://www.calsheriffs.org/
The Sierra County Clerk-Recorder (located at the courthouse in Downieville) has vital records, land records, mining records, etc. The Superior Court (upstairs) has naturalization records, probates, etc. Sierra County has birth records from 1857, marriage records from 1852 (when the county was formed from Yuba County), and death records from 1864. Some of the early records are incomplete but are well worth checking. They are almost all indexed!!
I live in Roseville (Placer County). If you are not aware, Roseville is just east of Sacramento and about two hours from Downieville. I go up when I can to do research (my g-g-grandparents arrived in Sierra County in 1859 and spent the rest of their lives there).
If you have any additional details, please send them to me. If you live outside of the area, I'll see what I can find when I go up next time.
Sierra County, CA GenWeb Coordinator