A tiny village on the Rio Grande River in northern New Mexico became the training center for the first American hydrographers and provided the first stream-gauging operations of the U.S. Geological Survey. To plan any water system, it is necessary to know the amount of water flowing in the stream or river at all times - including low, normal, and flood conditions.
El Camino Real (literally, "the royal road") is the oldest and longest historical trail in the Western Hemisphere. The transportation link has, through the centuries, been called various names, including El Camino Real de Tierra Adentro (literally, "the road to the interior" because the U.S. frontier was seen as the country interior to Mexico), the King's Highway and the Royal Highway. It became a transportation lifeline that helped integrate Spanish and European culture in the Southwestern U.S.
One of the first major efforts to increase farming and encourage habitation in the arid regions of the western United States, the Rio Grande Project was designed to provide reliable irrigation as well as resolve a dispute over water supply with the Republic of Mexico. The project's centerpiece is Elephant Butte Dam, a concrete gravity structure 301 feet high and 1,674 feet wide. Elephant Butte Reservoir - with a surface area of 36,600 acres and a capacity of more than 2.2 million acre-feet - was the largest reservoir in the world at the time of its completion.