|Eastbound Stacks from Same Location
|Westbound Beneath Manzano Mountains
|BNSF 5124 East Leads Stacks Under the Silent Gaze of Mount Taylor
|Eastbound Stacks Beneath Hidden Mountain, With Mesa Lucero Looming in Distance
|Stacks Meeting on Curve Near MP 27.8, With the Red World Beyond
Eastbound Manifest Showing Both Mount Taylor and Mesa Lucero
|Westbound Stacks on Right Pass Pushers on Eastbound Stacks, With Photographer Looking Up at Manzano Moutains
Even though the Rio Puerco is dry during much of the year, come heavy rains the channel carries huge quantities of soil downstream. I have read estimates that over one million acre-feet of soil have washed out of the river basin since 1885. Today, this river contributes only about four percent of water flow in the Upper Rio Grande watershed but almost 50 percent of the sediment. On August 7, 1957, the USGS recorded 2,240,000 tons of sediment passing through a stream gage three miles above the river's mouth.
Early Spanish explorers described the Rio Puerco as lined with cottonwoods so numerous that in the early 19th century a legal dispute arose over ownership of the timber. Today, cottonwoods have disappeared from the river. In 1692, Diego de Vargas, governor of the New Spain territory of Santa Fe du Nuevo Mexico, named the river La Torriente de los Alamos. "Alamos" are cottonwood trees, while "torriente" translates itself for an English speaker. Compare that to the images in this post to understand how drastically the landscape has changed in the past few hundred years.
Westbound Pushers on Oil Train Pass Eastbound Trailers
There is another theory for why the valley of the Rio Puerco has become so barren. In recent years, geologists have noticed that arroyos don't keep eroding indefinitely. At some point, tributaries begin to deposit sediment, and the arroyo begins to fill back in. Over hundreds of years, according to the theory, an arroyo erodes away, then fills back in, then erodes away, and over and over.
I have read articles arguing for fill cycles in the Rio Puerco from about 900 to 1250 A.D. and about 1325 to 1450 A.D., with a file cycle between these two dates. Between 1450 and 1880, filing appears to have been the dominant process. The erosion cycle that began about 1880, the results of which we see today, followed a period of about 500 years of fill, close to the average suggested in the literature. So perhaps the erosion of the past one hundred-plus years was not caused so much by over-grazing but rather by a natural erosion and fill cycle.
Eastbound Amtrak No. 4 Approaching Big Curve at MP 27.8
Westbound Oil Train on Curve to Due West Alignment
The image above is interesting because in the background it shows two distinct mountain ranges -- the Monzano Mountains to the right and the Sandia Mountains to the left. These mountains are part of a larger geologic unit known as the Sandia-Monzano Mountains -- a fault-block range in the Albuquerque Basin of the Rio Grand Rift. A fault-block occurs when there is vertical (rather than horizontal) displacement along a fault. I went to college at Stanford and vividly remember where a friend showed me a line of trees that had been planted in the late 19th century along the San Adreas fault. During the massive earthquake of 1906, at the point of the fault, the line of trees was displaced horizontally about nine feet.
The Manzano and Sandia Mountains were caused by a vertical displacement along a fault. Rather than moving sideways, the ground on one side of the fault moved upwards, creating a mountain chain. The Manzanos to the south are separated from the Sandias to the north by Tijeras Canyon, through which I-40 today follows the route of old U.S. 66. This canyon was much too rugged for a railroad line, which is why the AT&SF originally came to Albuquerque from the north and then latter by-passed the town altogether on the Belen cut-off.
At approximately MP 30, the Transcon curves to due west in a location that is easily accessible from New Mexico State Highway 6. Many times I have set up my tripod just slightly beyond the shoulder of the highway and photographed westbounds roaring down the hill.
Westbound Amtrak No. 3 Passing Eastbound Stacks, Turning Due West Beneath Manzano Mountains
As you can see, the land here is quite barren, and I have spent many hours hiking through this territory, looking for the perfect shot -- which I have not yet found. I have never had any trouble from land-owners. In fact, my guess is that the people who live out here don't own the land. Fee title is probably held by someone in Albuquerque or Denver who never sets foot in this desert.
DPUs on Eastbound Stacks
More Eastbound DPUs
For most of my life, I have assumed that the landscape changes only across hundreds of thousands, or even millions, of years. After reading the literature on the Rio Puerco, however, I realize that significant changes can occur across two or three human generations. Thus, late in life, I have begun to pay more attention to the geology around me, because I now know that what I am seeing may not have been here a century ago, and may not be here a century from now. The idea that changes in the earth's geology can occur so rapidly is, to me, astounding, as though someone had told me as a teenager that 40 years hence I would consider all teenagers foolish. Who would have thought that?
Westbound at Same Curve, With Warbonnet and NS Power
As the tracks straighten to due east-west, one can photograph eastbound trains climbing the grade, with Ladron Peak in the background. Ladron is the only peak in the Sierra Ladrones (Mountains of Thieves). Despite its conical shape, it is not a volcano. Instead, Ladron Peak is a single, large massif lying between the Rio Puerco and Rio Salado. A massif is a section of the earth's crust, more rigid than surrounding rock, displaced (uplifted) as a unit. The core is Precambrian granite, and the summit is almost 5,000 feet above the Rio Grande Valley, 10 miles to the east. The mountain supports vegetation and wildlife not found on the desert below. Pine forests grow on its upper slopes. Animals living on Ladron Peak include bear, pronghorn, elk and deer.
Eastbound Stacks Beneath Ladron Peak at Sunset
Another Eastbound at Dusk Beneath Ladron Peak
Westbound Amtrak No. 3 at MP 31.9
Mile Post 31.9 is where we end this particular journey, not because there is nothing more to see but rather because it sits almost on top of the Rio Grande Rift. From here westward, the Transcon gently climbs the Colorado Plateau to the Western Continental Divide. I will discuss this section of the line in subsequent posts.
Westbound Autos at MP 31.9
Trailers at Dusk
As you stand south of the tracks at MP 31.9, a one-hundred eight degrees turn late in the day will reveal eastbounds pounding up the grade in the late afternoon sun. This is one of my favorite locations in New Mexico, and I leave you with these fading images until next time. Via con Dios.
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