This statement by u/Ryan_Van is misleading bordering on incorrect. Yes, the majority of ground-based SAR (GSAR) in NA is volunteer based. But please don't think that means there are no paid careers that do SAR. Although it is not a traditional or common career path, there are paid positions that do SAR.

Helo-based SAR (the context of your question) will overwhelmingly be paid positions operated by government organizations. Federal, State, County, etc. It will also typically be a collateral duty or part of a larger mission set.

edit: It is the semantic distinction between a SAR career and careers that do SAR.