Historically significant as the capital of the Chickasaw Nation, Tishomingo is on Lake Texoma. After serving as the last Chickasaw National Capitol , the granite Victorian Gothic building at N. Capitol Avenue and W. 9th Street housed the Johnston County Courthouse 1907-89. Guided tours of the building are available; phone (580) 371-9835. The restored 1902 Indian Territory Bank of the Chickasaw Nation, a block from Court House Square, houses the Johnston County Museum of History. Learn More...