Also called mounted patrols, reserve deputies, special deputies, or auxiliaries in some localities, posse members are fully trained to perform their specialized tasks. Some are specialists restricted to certain areas, such as boat or snowmobile safety, communications, paramedic response, search and rescue, or the use of aircraft in law enforcement. These units permit a sheriff to strengthen operations with little additional cost. Some examples of the use of posses are in the search for a kidnapped boy in Dakota County, Minn.; the Sheriff's auxiliary in Green Valley, Ariz., which controls traffic at accident sites, aids in search and rescue missions, and checks houses left vacant by summer travelers; and the volunteer reservists in Pickaway County, Ohio, who include persons skilled in underwater recovery and the establishment of a command post with state-of-the-art communications. Other posses described in this article are in Woodbury County, Iowa; Anoka County, Minn.; Jackson County, Ky.; and Ramsey and Hennepin Counties, Minn.