Albuquerque area, the Middle Rio Grande Conservancy District (MRGCD or just "The District"):

The dikes, levees and canals the MRGCD built in the 1930's are still in service for the most part. They're woven into the dense fabric of farmland, roadbeds, residential neighborhoods and industrial districts. Although this was probably the largest engineering project of the twentieth century, much it has been subsumed by fifty new miles of urban growth, (or sprawl depending on your point of view). 

The exception to this expansion is along the riverbanks and marshes known as The Bosque. Approaching the Rio Grande from the east on any surface level road, you see the telltale canopy of Cottonwood trees. Bridges on Central Avenue (Route 66) and Corrales Road have parking areas  entrance is through the Rio Grande Nature Center on Candelaria Avenue. www.rgnc.org/

The most prominent features of the MRGCD's work are the puzzling and somewhat sinister "deadman jacks". They were apparently supposed to be planted below grade to prevent soil erosion, but they stand today in ranks that resemble WW1 defense armaments. Perhaps they were. Unfortunately, information is as inaccessible as most of the notable structures built by the District.

An exception is the Angostura dam north of Bernalillo. La Angostura, "narrow point" provided a strategic advantage for military garrisons: control of the wider valley that spreads north and south of this site.

The head gates of this diversion dam regulate the entire network of irrigation channels in the Albuquerque Basin. When the MRGCD built it in the 30's, with help from the US Army Corps of Engineers, the Chief Engineer described it this way:

"The Angostura Diversion Dam is a low flat "Indian" type weir founded on sand and gravel. It has a total length of 938 feet, including the sluiceway. …. The sluiceway section, located at the easterly end of the dam, consists of five openings each 20 feet wide, controlled by five radial gates 20 feet wide by 6.4 feet high…."

At this unheralded site, you can stand on the benchmarks of civil engineering that transformed the economic future of the region.