Striking Rules

Recently there was a ski patrol union strike in the park city Utah area. It was successful and the company agreed to increase wages and improve benefits, concluding the strike after about 2 weeks.

I know police, fire, and paramedics are “prohibited” from striking in most US jurisdictions.

Was wondering how ski patrol was exempt from these laws? (Many provide EMS, how is this different than 911 EMS?)

Also, what do these laws mean by “prohibit” (in regards to striking).

For example, what would not-being prohibited from striking mean? As opposed to prohibited? Wouldn’t employers feel the same about your strike whether it was allowed or not?

Is it criminal to not show up to work? Or would you be liable civilly? Could you be fired for cause?

Help me figure this out.

[I’m a happy union firefighter/paramedic, not considering striking but curious about the topic.]