Utah Code § 41-6a-1403: Motor vehicle left unattended -- Requirements.

(1) A person operating or in charge of a motor vehicle may not permit the vehicle to stand unattended without:

(a) stopping the engine;

(b) locking the ignition and removing the key;

(c) placing the transmission in "park" or the gears in "low" or "reverse" if the vehicle has a manual shift; or

(d) effectively setting the brakes thereon.

(2) A person shall turn the front wheels to the curb or side of the highway when standing a vehicle on any perceptible grade.