Well, I wouldn't say there's NO recourse. If the sheriff is implicated in the breaking of a law, BCI can surely investigate, as can the feds.
If it just comes down to not liking the sheriff, well...it's an elected position. Take it to the voters or maybe even the county commission. We've seen the CC move to remove sheriffs a few times over the past several years. If nothing else, the governor acting on recommendations from the CC can remove a sheriff. Which, is what I think happened not that long ago in Mckenzie County. I think it has something to do with it being an elected position but maybe someone with a better background in law can help us understand the mechanisms.