“It’s a twister! It’s a twister!”
Or at least it looked like one. In any event, the driving conditions during what was supposed to be our relatively short ride from Gunnison to La Junta, CO were certainly less than ideal. The wind slapped and banged at the truck in irregular bursts, and spooky tumbleweeds rolled across the road in the hundreds; the landscape churned with bits of grass and dead plants. Looking further up the highway, we saw a hazy, brown cloud that resembled a fire.
We soon realized that the “fire” was actually a rolling cloud of sand and dust formed by the fierce winds blowing out from the thunderstorm. Lucky for us, visibility was only slightly reduced. Here, take a look:
The area surrounding our sample site at the Alamosa/San Luis Valley contains the highest agricultural land in the United States. Here, elevations average around 7500 feet, with surrounding peaks over 14,000 feet. Local farmers specialize in “cool season crops” like potatoes, head lettuce, and barley. In fact, Coors beer (love it or leave it) is made exclusively from barley grown here in the Intermontane Plateaus of the Colorado Plateau Province.
Regional soils broadly consist of two types—the soils of alluvial fans and floodplains located at the valley floor (which we sampled), and those found on the hills and mountains. Had the weather permitted, with a little more digging around we would have expected to come across Colorado’s state soil, “Seitz soil,” which consists of very deep, well-drained, slowly permeable soils formed from igneous, sedimentary and volcanic alluvium. Seitz soils are abundant near the valley edges and on mountains, mainly in southwestern and central Colorado.
This was definitely one of the dustiest places we encountered; the valley regularly experiences periods of drought, with most precipitation occurring either during the winter months as snow, or during the short, summer monsoon season. However, much of the moisture from these precipitation events is lost through evaporation due to the region’s characteristically clear skies and dry, thin, high-elevation air. Thus, it comes as no surprise that the dry, heavily cultivated soils of the Intermontane Plateaus are easily influenced by the summer storm systems and strong winds.
After we arrived in La Junta, we discovered that several tornadoes had indeed touched down in northeast Colorado—hundreds of miles from where we’d been driving. Oh, well—we’re geochemists, not meteorologists.
P. S. Dust isn’t the only thing the La Junta wind transports (my sleeping bag exploded). Hopefully local birds and other critters have since put the down feather to good use.