Pecos National Historical Park, 6,671 acres (2,702 hectares), N New Mexico; est. as a national monument 1965, designated a national historical park 1990. The park contains the remains of the Pecos pueblo, a major trade center strategically located between the Great Plains and the Rio Grande Valley. The Pecos site was excavated from 1915–29 by Alfred V. Kidder and is considered the first major archaeological dig using modern scientific techniques. In 1999 nearly 2,000 skeletons that had been excavated there were returned to the inhabitants of modern Jemez and reburied at Pecos. Two Spanish colonial missions are also preserved, as well as sites associated with the Santa Fe Trail and the 1862 Civil War battle of Glorieta Pass. A 2-mi (3-km) segment of the Pecos River is protected in the park.