St. Tammany Fire Protection District No. 4 encompasses an approximate 78 square mile region on the Northshore of Lake Pontchartrain in Southern Louisiana. The District boundaries are formed by the fourth ward of St. Tammany Parish. It is bordered to the east at Pontchartrain Drive on Highway 190, west to the Tchefuncte River, north to Ponchitalawa Creek (including additional areas along LA Highways 36, 59, Interstate 12, Helenburg Road and the River Oaks subdivision), and south extending 13.4 miles on the Greater New Orleans Expressway (Causeway).