The Guadalupe Mountains () are a mountain range located in West Texas and southeastern New Mexico. The range includes the highest summit in Texas, Guadalupe Peak, , and the "signature peak" of West Texas, El Capitan, both of which are located within Guadalupe Mountains National Park. The Guadalupe Mountains are bordered by the Pecos River valley and Llano Estacado to the east and north, Delaware Mountains to the south, and Sacramento Mountains to the west. One of the clearest exposures of a prehistoric reef is preserved in the mountain range's bedrock geology. Bedrock contains fossils of reef-dwelling organisms from the Permian period, and the geology is widely studied, mostly by stratigraphers, paleontologists, and Paleoecologists (see geology section). History Archaeological evidence has shown that people lived over 10,000 years ago in and among the many caves and alcoves. The first humans to live here were hunter-gatherers who followed large game and collected edible vegetation. Artifacts that support this include projectile points, baskets, pottery, and rock art. The first Europeans to arrive in the area were the Spaniards in the 16th century, but they did not make serious attempts to settle in the Guadalupe Mountains. The Spanish introduced horses into the area, and nomadic indigenous tribes of the area such as the Apaches soon found horses to be an asset for hunting and migrating. Mescalero Apaches were nomadic and followed the game and harvested the agave (or mescal) for food and fiber. Mescalero is Spanish for mescal-maker. Agave-roasting pits and other artifacts of Mescalero culture can be found in the park. The Mescalero Apaches remained in the mountains through the mid-19th century, but they were challenged by an American transportation route at the end of the American Civil War. During the 1840s and 1850s, many people immigrating west crossed the area. In 1858, Pinery station was constructed near Pine Springs for the Butterfield Overland Mail. The Butterfield Overland Mail traveled over Guadalupe Pass located at above sea level. A cavalry was known as the Buffalo Soldiers was ordered to the area to stop Indian raids on settlements and mail stage routes. During the winter of 1869, Lt. H.B. Cushing led his troops into the Guadalupe Mountains and destroyed two Mescalero Apache camps. The Mescalero Apache were eventually driven out of the area and into US Indian reservations. Felix McKittrick was one of the first European settlers in the Guadalupe Mountains; he worked