imported post
He may carry unloaded (no chambered round, full mag) assuming he is 18 or older, and not in a school zone.
Here is why, public street is undefined.
76-10-505. Carrying loaded firearm in vehicle or on street.
(1) Unless otherwise authorized by law, a person may not carry a loaded firearm:
(a) in or on a vehicle, unless:
(i) the vehicle is in the person's lawful possession; or
(ii) the person is carrying the loaded firearm in a vehicle with the consent of the person lawfully in possession of the vehicle;
(b) on a public street; or
(c) in a posted prohibited area.
(2) Subsection (1)(a) does not apply to a minor under 18 years of age, since a minor under 18 years of age may not carry a loaded firearm in or on a vehicle.
(3) Notwithstanding Subsection (1)(a)(i) and (ii), a person may not possess a loaded rifle, shotgun, or muzzle-loading rifle in a vehicle.
(4) A violation of this section is a class B misdemeanor.
76-10-502. When weapon deemed loaded.
(1) For the purpose of this chapter, any pistol, revolver, shotgun, rifle, or other weapon described in this part shall be deemed to be loaded when there is an unexpended cartridge, shell, or projectile in the firing position.
(2) Pistols and revolvers shall also be deemed to be loaded when an unexpended cartridge, shell, or projectile is in a position whereby the manual operation of any mechanism once would cause the unexpended cartridge, shell, or projectile to be fired.
(3) A muzzle loading firearm shall be deemed to be loaded when it is capped or primed and has a powder charge and ball or shot in the barrel or cylinders.