(a) To carry out the functions of the department, the chief shall employ county park rangers as peace officers and shall employ administrative staff in numbers approved by the commissioners court.
(b) The county park rangers have the same law enforcement authority that is given by law to deputy sheriffs except that the law enforcement jurisdiction of rangers is limited to the county parks of the county and, in a county that borders the Gulf of Mexico, to the unincorporated areas of the county that are located on an island or isthmus.
(c) The law of this state applying to deputy sheriffs applies, to the extent practicable, to county park rangers.