The Mid-Region Council of Governments' (MRCOG) region consists of the counties of Bernalillo, Sandoval, Torrance, and Valencia as well as the southern portion of Santa Fe County.

As the center of the state, the region literally lies at the crossroads of New Mexico. Busy interstate highways, rail and an international airport link the region in the same way historic trade routes linked the original Indian tribes hundreds of years ago and tied the Spanish settlements 300 years ago.

It’s a region of remarkable diversity, in population, lifestyle and economy. About the size of Massachusetts, the area is both urban and rural, mountain and plains, modern and traditional. Central New Mexico includes Albuquerque, the state’s largest city; Rio Rancho, the state’s fastest-growing city; Bernalillo, one of the nation’s oldest towns and even older Indian pueblos; and Edgewood, the state’s newest community.

And it’s a place of great beauty, with four mountain ranges, the legendary Rio Grande, two national forests, two national monuments, three wilderness areas, four state monuments and parks, and two game refuges.

The largest municipalities of 19 incorporated communities shown in the map below are: Albuquerque, Rio Rancho, Los Lunas, Bernalillo and Belen. There are also twelve Indian Tribes and Pueblos that are entirely or partly located within the region, and the three largest; Isleta, Santo Domingo and San Felipe, each had a population of about 3,200 in 2000.

The MRCOG Region has experienced significant growth. The population of roughly 843,000, 43 percent of the state’s population, has more than doubled in the last 30 years. Between 2000 and 2006, the four-county area grew 14.1 percent, from 738,000 to 843,000. Population in the region is expected top 1 million by 2020, with an annual growth rate of 1.5 percent. By comparison, the annual growth rate in the previous 30 years was 2.4 percent.

Led primarily by Rio Rancho, Sandoval County has recently experienced rapid growth and will continue to be the fastest growing county in the region. The Edgewood area of southern Santa Fe County has also experience rapid growth, compounded by an expanded Town Boundary. Other significant population growth is anticipated for northern Valencia County and Albuquerque’s Southwest Mesa and Northwest Mesa. The population on tribal lands in the four-county area is expected to rise from roughly 19,000 in 2000 to 25,000 in 2020.

The economy, once dependent on defense spending, has diversified and now includes healthy high tech, service, and manufacturing segments. Albuquerque is a regional health, finance and trade center. It’s home of the state’s largest university and technical-vocational school, as well as Sandia National Laboratories and Kirtland Air Force Base.

History

Central New Mexico has been continuously occupied for some 12,000 years, from the time paleo-Indian people built their first villages along the Rio Grande, to occupation by the farming Pueblos. 

Rio Grande River
photo by Marble Street Studio

In 1540 Captain Hernándo de Alvarado and his soldiers became the first Europeans to see the Middle Rio Grande Valley. They were the advance guard for the Spanish explorer Francisco Vázquez de Coronado. Approaching from the west, Alvarado looked down into a broad, grassy valley along a river that Pueblo Indian people had used for centuries to irrigate their crops.

The first colonists arrived about 50 years later. Don Juan de Oñate, sometimes called The Colonizer of New Mexico, claimed the northern frontier of Nuevo Mexico for Spain in 1598, nine years before the English settled Jamestown. In the 1660s, the first settlers began farming in the Middle Rio Grande. The first communities established were Bernalillo, 1695; Atrisco, 1703 (now an Albuquerque neighborhood); Albuquerque, 1706;  Los Lunas, 1716; and Belen, 1741.

The early communities would prosper as agricultural centers and carry on trade to the north and south over El Camino Real, the Royal Road. This critical trade route would later become U.S. 85 and then I-25. Similarly, east-west trade routes would link the Middle Rio Grande to the plains and to settlements in the west. First the railroad and then Route 66 and I-40 would follow these old trails.

In 1821, when Mexico won its freedom from Spain , New Mexico became part of Mexico . In 1846 the United States claimed New Mexico, and the Middle Rio Grande Valley gained access to vast new trade areas over the new Santa Fe Trail.

The Atchison Topeka & Santa Fe Railroad reached Albuquerque in 1880, bringing the world, literally, to the Middle Rio Grande. Albuquerque’s economy would be reliant on the railroad until the 1940s, and Belen would become a rail hub in 1907 with the completion of the Belen Cutoff, which saved 10 hours on the Chicago run.

In the 1930s, Route 66 began to snake across New Mexico, originally passing through Santa Fe in the north and making its way south through Bernalillo, Albuquerque and Los Lunas, before reaching west. Later the road was straightened to pass directly through Albuquerque. Just three decades later, interstate highways would begin to eclipse Route 66, just as Route 66 had eclipsed the railroad. Today more than 95 percent of the region’s population lives within 30 minutes of an interchange on I-25 or I-40.

When New Mexico became a state in 1912, the region’s population was small. With World War II and post-war growth, the population spiraled during the 1940s and 1950s and continued a rapid climb through the 1980s, as the economy diversified. 

The University of New Mexico Bureau of Business and Economic Research has for some time disagreed with population-growth projections of the U.S. Census Bureau. BBER demographic research shows that the Census Bureau’s estimates have been erroneously low from the mid-1990s to the present. 

Geology

Sandia Mountains: In the dawn of geologic history, about 150 million years ago, violent forces wrenched the earth’s unstable crust. In some places heat melted underlying rock, which burst to the surface as volcanoes. In other places, mountains rose, but thousands of years of erosion by wind, rain and snow would wear them down.

Here, in Precambrian time, the underlying rock didn’t break to the surface but instead cooled and solidified to form granite. Later, stresses moved and lifted the granite up, breaking it into blocks. This formed the core of the Sandia Mountains.

About 300 million years ago, great inland seas began to cover the area and then retreat. The waters carried suspended sediments as well as marine life. When they retreated, they left behind layers of limestone, sandstone and shale, which capped the Precambrian rock. This is why you can see marine fossils in the limestone caprock of the Sandias. At times exposed land would be subject again to erosion before dropping again beneath the water, which then continued to add deposits. This process went on for hundreds of millions of years. Around 70 million years ago, in the late Cretaceous Period, there was an upheaval of the earth’s crust, which pushed up the Rocky Mountains, including the Sangre de Cristos, which are the southernmost extension of the Rockies. 

About seven to ten million years ago, heat and compression broke the earth’s shell, causing a crack, or fault. On one side of the fault, the earth rose sharply, creating a sheer bluff that faced west. This exposed layers of rock deposited in previous ages, along with the Precambrian granite. Geologists estimate that the total vertical rise of the fault is about five miles. The same rocks we see on top of Sandia Crest are also miles below the surface.

Erosion began wearing away the layers and rock, creating the Sandias and the Manzanos as we know them. The Sandias and Manzanos are not part of the Rocky Mountains because they formed much later and by a different process.

Today the Sandias have two distinct peaks – North Sandia Peak, 10,678 feet, and South Sandia Peak, 9,782 feet. In between is a saddle known as Sandia Crest. The knobs, columns and pinnacles on the western side were created by erosion, which also created canyons.  

The Sandias are about 20 miles long and end in the south at Tijeras Canyon. “Tijeras” means “scissors” in Spanish. Here, various companies have made cement from the limestone, dolomite, shale and gypsum since 1957.

As granite blocks rose to create the Sandias, the land west of the fault dropped, leaving a depression called a rift. Similar movements created a string of depressions from southern Colorado to northern Mexico called the Rio Grande Rift. In the Albuquerque area, the Rio Grande Rift Valley is about 30 miles wide, with one fault at the base of the Sandia Mountains and the other fault to the west near the Rio Puerco. It’s one of the few young continental rift valleys on the planet. A rift is a place in the Earth’s crust, where the crust is thinning and pulling apart.

This rising and falling took place slowly, and continues to this day. The Sandias and Manzanos continue to rise, and the valley continues to drop.

Over time the rift filled with sand, gravel, silt, clay and rocks carried by water, gravity and wind from nearby mountains. This porous material reached 10,000 feet deep, and it has collected water for thousands of years. Communities along the Rio Grande have relied on this store of water, called an aquifer, for over a century. 

Manzano Mountains: The Manzanos, which stretch for 40 miles south from Tijeras Canyon to U.S. 60, are a continuation of the tilted fault block that created the Sandias. The exposed granite on the west face formed 1.5 billion years ago below the surface. Its limestone cap, like that of the Sandias, holds fossilized shell and coral. The Manzanos began rising about 20 million years ago as the Rio Grande Valley began subsiding. Its serrated west face hides deep canyons, gorges and springs. Its summits are the 10,098-foot Manzano Peak and the 10,003-foot Osha Peak.

Rio Grande: During the Ice Age, sheets of ice extended south from the North Pole. They didn’t reach this area, but mountain glaciers formed in the high mountains. As the climate warmed, these glaciers moved and melted, expanding valleys and carving channels for rivers as they progressed.
High in the Colorado Rockies, melting glaciers fed a powerful stream, which pushed south toward the sea, carrying rock and earth with it. At present-day Albuquerque the river filled in the Rio Grande Rift with sediment and then began to erode the river bed it had just created, carrying debris downstream. The river’s cycle of deposits and erosion has continued now for thousands of years and is still in progress.

Until recent years, the river meandered over a wide floodplain, depositing silt. As the riverbed rose, the Rio Grande would break out of its channel and take a new path.

Pueblo people learned to live with the meandering river, but as Spanish settlers established farms along the river after 1598, flooding became a problem. In addition, the river created mud flats, marshes and ponds, and quicksand was a danger when crossing the river in certain places. But anyone wanting water had only to dig a few feet.

The untamed Rio Grande vexed the city until organized efforts at flood control began in 1925 with the creation of the Rio Grande Conservancy District. In time a network of dams, drains and diversion channels confined the Rio Grande and stopped its meandering. Drought and increasing use of wells lowered the water table and eliminated the swamps. 

Volcanoes: About 150,000 years ago – just yesterday in geologic time – a north-south fracture opened west (in the middle of the rift) and nearly parallel with the river. Lava exploded from multiple places along the faults because the Earth’s crust was thinner and the magma was closer to the surface. At six of these places, lava and ash would form volcanic cones. From these, lava bubbled and spread towards the river, hardening into a cap of basalt.

Within the last 100,000 years, the softer alluvial soils began to erode from underneath the basalt, and the layer of basalt tumbled down in boulders along an edge, or escarpment. 

Today five volcanic cones are visible on Albuquerque’s West Mesa. A sixth volcano disappeared because it was mined for scoria, red lava rock. 

Jemez Mountains: Violent volcanic activity also created the Jemez Mountains in north-central New Mexico on the western edge of the Rio Grande Rift. One of the state’s most prominent mountain ranges, the Jemez Mountains are 1,300 square miles, with peaks ranging between 9,000 to 11,000 feet. Eruptions began 13 million years ago. One of the most prominent features is the Valles Caldera and its surrounding ridges, created in one volcanic explosion of such force that it showered materials as far away as Kansas. The highest point in the range is 11,561-foot Chicoma Mountain. Redondo Peak, the second highest peak at 11,254 ft is in the middle of the Valles Caldera. 

Weather and Climate
The climate varies with elevation, but most of the region is semi-arid, with abundant sunshine, low humidity, and about 10 inches of annual precipitation. Temperatures range from 92-65 F in July to 47-23 F in January, with an average of 304 sunny days per year.

Visit Regional Data for a more detailed report of historical and future statistics on the region, including population, age, race, education, housing, etc.

Contact:  Kendra Watkins ( This e-mail address is being protected from spam bots, you need JavaScript enabled to view it )