In 1899, the United States conducted its first census of Puerto Rico, finding that the population of Culebra was 704. In 1902, Culebra was integrated as a part of Vieques. One year later, on June 26, President Theodore Roosevelt established the Culebra Naval Reservation. A bird refuge was established on February 27, 1909. In 1939, the U.S. Navy began to use the Culebra Archipelago as a gunnery and bombing practice site. This was done in preparation for the United States' involvement in World War II. In 1971 the people of Culebra began protests, known as the Navy-Culebra protests, for the removal of the U.S. Navy from Culebra. Four years later, in 1975, the use of Culebra as a gunnery range ceased and all operations were moved to Vieques. Culebra was declared an independent island municipality in 1917. The first democratically elected government was put into place in 1960. Prior to this, the government of Puerto Rico appointed delegates to administer the island. Culebra is an archipelago consisting of the main island and twenty-three smaller islands that lie off its coast. The largest of these cays are: Culebrita to the east, Cayo Norte to the northeast, and Cayo Luis Peña and Cayo Lobo to the west. The smaller islands include Cayo Ballena, Cayos Geniqui, Arrecife Culebrita, Las Hermanas, El Mono, Cayo Lobito, Cayo Botijuela, Alcarraza, Los Gemelos, and Piedra Steven. Islands in the archipelago are arid, meaning they have no rivers or streams. All of the fresh water is brought from Puerto Rico via Vieques by undersea pipeline. Culebra is characterized by an irregular topography resulting in a long intricate shoreline. The island is approximately . The coast is marked by cliffs, sandy coral beaches and mangrove forests. Inland, the tallest point on the island is Mount Resaca, with an elevation of , followed by Balcón Hill, with an elevation of . Ensenada Honda is the largest harbor on the island and is considered to be the most hurricane secure harbor in the Caribbean. There are also several lagoons on the island, like Corcho, Flamenco, and Zoní. Culebrita Island also has a lagoon called Molino.