The superintendent, the assistant superintendent, and the troopers constitute the highway patrol. The highway patrol shall enforce the provisions of the laws of this state relating to the protection and use of highways and shall patrol the highways and cooperate with sheriffs and police in enforcing the laws regulating the operation of vehicles and the use of highways. All troopers and the assistant superintendent must be appointed by the superintendent. Each trooper appointed is deemed a probationary employee for an initial period of six months, during which the trooper must be placed under probationary training and service and is subject to an extension of an additional period of six months or dismissal at the will of the superintendent or the superintendent’s designee. At the end of the probationary period, a probationary employee must either be taken off probationary status or dismissed. A nonprobationary employee employed in a regular, classified position is subject to removal for cause by the superintendent or the superintendent’s designee, but the employee may appeal a dismissal under chapter 54-44.3 provided the removal of the assistant superintendent from the assistant superintendent position does not entitle that person to appeal the removal unless that person also is dismissed from the patrol.