The Sheriff is the highest law enforcement authority. They supercede the Feds, AFAIK.
The prosecutor is the highest law enforcement authority in the county.
When Canadian grey wolves were re-introduced in Idaho in the mid-1990’s, they killed a local rancher’s Angus calf and “someone” shot and killed the wolf. The Fed wildlife gestapo moved in and tried to arrest the rancher; in stepped the county sheriff who told the feds to pack up and get the hell out of his county.
A brief armed standoff occurred, but the feds backed down.
We have so many idiot feds running around armed in vehicles with lights all over them it feels like a police state. The stupid BLM and US Forest Service have armed law enforcement nitwits driving around acting important.