Tamaulipas (tämoulēˈpäs) [key], state (1990 pop. 2,249,581), 30,734 sq mi (79,601 sq km), NE Mexico, on the Gulf of Mexico. Ciudad Victoria is the capital. The central and western parts of the state are in the mountains of the Sierra Madre Oriental. In the north and south are arable plains, particularly in the long panhandle beginning at Nuevo Laredo and following the Rio Grande opposite Texas to Matamoros. The coast is low, sandy, fringed with lagoons, and (except for Matamoros and Tampico) only lightly inhabited by fishermen and a few resorts. The extreme southwestern mining area borders on the vast semiarid basins of central Mexico. Except in the elevated interior, the climate is hot and humid. The state's greatest source of wealth is petroleum and its byproducts, but agriculture and cattle raising are also important. Tamaulipas is a leading national producer of sugarcane and cotton; cereal grains and tobacco are other major crops. Maquiladoras, foreign-owned manufacturing plants that finish goods for U.S. export, have rapidly grown throughout the state. The Spanish first explored the territory in 1519, but after conquering the Tamaulipans they abandoned the area. European colonization began in 1747; Franciscan missions flourished in the 18th cent. Drug-related violence has been a significant problem in the early 21st cent. in the state's cities that border the United States.