It isn't so much the location that matters- it is the expectation of privacy.
Nevada is a one-party state, meaning only one person involved in the conversation must be aware of the recording, unless it is over the phone then both must consent.
Even without consent, audio recording where there is no reasonable expectation of privacy is still legal. It is possible to have a private conversation in a public place, so the specific circumstances must be known to say for sure what consent is required, if any.