Local law enforcement call signs in South Dakota typically start with the county number. For example, 46-1A is the call sign for McCook County Sheriff. The number 1 in the call sign indicates that it is a sheriff unit. If a smaller town has PD officers, their call sign will have a 2 in it. For example, 37-2B would be a police officer from one of the towns in Hutchinson County. Most of the larger cities in South Dakota use badge numbers for call signs. As far as State Troopers, the State assigns them a call sign. For example, HP169. Most State Trooper supervisors have lower number, usually under 30. For example, HP27.