Teacher Appreciation Week 2024

The Fremont people could not change the climate, but they could change how they lived in response to it. A hot dry climate or a cold climate reduced corn production, so they might have needed to find more food for their families. A warm wet climate meant that they might have had more food than they needed and could have traded with others. Sometimes the weather within the Fremont homeland in any given year was hot and dry in one area and warm and wet in another.

Archaeologists think that Fremont people responded to changes in climate in two general ways. The first is where and how they lived. They could choose to move to another area within the Fremont homeland or they could move higher in elevation where the weather was cooler. They could choose to live in large villages where they could work together to irrigate fields and grow more food, or they could live in family groups and farm over a wider area to take advantage of small, scattered water sources.

Archaeologists have identified evidence that the Fremont people responded to climate change by changing the way they interacted with each other. In larger villages people who wanted to trade food or other items could have more choice. The Fremont may have chosen leaders who directed how food was shared or traded. Perhaps, they built public buildings and developed practices to help each other, much like churches or towns organize to help each other today.

Tree Ring Dating and Climate Change

Archaeologists work with other scientists to reconstruct the climate that past people like the Fremont experienced by studying tree rings. Trees add two rings of growth each year, which you can see in a cross-section of a tree called a tree cookie. A light-colored ring grows during the spring and early summer. In a warm and wet year, a tree grows a lot and creates a wide ring. A dark-colored ring grows in the late summer and early fall when growth slows. Many wide rings together, show that the climate was good for all plants in that area for several years. Narrow light-colored rings show that the climate was unfavorable for all plants, including corn.

But how do we know when the climate was either good or bad for plants? Another very useful thing about tree rings is that they can be used to determine when a tree lived. The first ring inside the bark records the last year of growth. We can create a master sequence of wide and narrow rings by overlapping tree cookies, starting with a tree cut down this year. We can then find older and older trees from the area, like we see in the Master Sequence illustration (free sample lesson plan). All trees in the same region will grow wide or narrow light-colored rings in response to the same weather conditions, which makes it possible to compare specific growth years across time.

Archaeologists create a master sequence of tree rings in an area like the Fremont homeland by drawing vertical lines on a piece of paper at the end of each tree ring. We know the age of each of these lines because we start with a line representing a tree that was cut down this year. We then count backwards, with each dark ring representing one year of growth.

Both archaeology and the oral histories of descendant Native Americans have much to tell us about climate change and the adaptations people have made to these changes including remarkable local adaptations. For example, when farming was feasible in the region that is now Utah, the Fremont people lived primarily on a diet of corn and other cultivated plants supplemented by wild foods gathered from the surrounding landscape. When farming was no longer tenable, the Fremont and their descendants shifted back to a more nomadic foraging lifestyle. Both adaptations were well-suited to the climate.