by Andrew Bierbower

As we landed at Denver International Airport to begin our seven-day field excursion in Colorado, we felt a sense of the large, raw scale we lacked in Houston. Looking out of the terminal windows to the west, the Front Range of the Rocky Mountains loomed large in the distance, across a vast plain of rolling hills; even the walk through the airport to the rental car pick-up seemed huge. As we piled into our rental van, Stewart Williams, a graduate student, encouraged us to take in the climate and topography as we began our drive west towards Minturn.

The most immediate change we noticed from Houston is the temperature. 77 degrees and below 40% humidity felt inviting, beckoning us to explore and was a far cry from the 100 degrees Houston was experiencing that day. The hilly plains surrounding the airport and city of Denver are soft and seemingly roll on forever over the horizon to the north and south. As we start getting into the higher topography of the Front Range towards the Rockies, Stewart points out one of the many visually striking features of the area: hogbacks. These massive slabs of sandstone are tilted at more than 30 degrees from horizontal, protruding out from the ground at random intervals, seemingly standing silent guard against anyone who dares try to conquer the Rockies. This striking feature formed as the basement rock of the current Rocky Mountains began to be uplifted, faulting and deforming the sedimentary layers that lie above. Erosive processes chipped away at the softer Morrison Formation silt and mudstones, leaving the well-cemented Dakota Formation ridges in their awe-inspiring positions we see today.

For lunch, we stopped at Genesee Mountain Park, nestled in the mountains outside of Denver. As we pulled in, we noticed a herd of bison who were lounging and grazing in a nearby field. Dr. Masiello gathered us around to explain how the bison and local grasses are locked into an evolutionary arms race of sorts. The bison graze on grasses that absolutely do not want to be eaten so the grasses have developed defenses by incorporating phytoliths or silica “bones” that grind down the teeth of would-be grazers. In turn, the bison have evolved teeth that continue to grow throughout their life in an attempt to counter these grasses.

Arriving at the Eagle River Inn gives us a chance to relax for a bit before we deployed transducers in and along the Eagle River. These will be used to detect the water pressure, temperature, and depth, with another transducer placed along the river bank to track atmospheric pressure. To no one’s surprise, the glacial-fed river is cold! Cold as in take your breath away cold! It was also much, much deeper than it seemed, with a sharp drop-off from the shallow banks it created. With these transducers deployed, lecturer Zhuoya He is attempting to track the natural and daily changes of water depth and pressure within the Eagle River.

Later that evening, we all piled back into the van for a quick trip up the road to a beaver-engineered meadow. We met with Tayler Branson from the Walking Mountains Science Center who gave us some background information on the beavers themselves. Did you know that an adult beaver can eat over 200 aspens a year? They are also mostly nocturnal, spending most of their waking hours from the evening until the morning. While we walked towards the location of the beaver lodge, Tayler occasionally stopped us to show us signs of beaver activity, like beaver chews and explained that they preferred softer, woodier trees over harder woods, like pine. Eventually, we arrived at the still pond that this beaver family had decided to call home.

Only when you sit down and observe the beaver dam and lodge do you begin to see the impact it has on the local ecosystem. The still water provides a place for insects to land in search of a mate. This in turn provides an opportunity for local fish to catch an evening snack. Nearby, a mother and father goose raise two goslings in the tranquility and safety of the pond. Various birds and waterfowl find chances for dinner on the banks and in the marshy grasses. Eventually, a beaver does appear, lazily munching on snacks it dives for at the bottom of the pond, all the while, unaware of its impact on the biodiversity of the surrounding ponds it has engineered.