How the unknown has changed - Kathy Conn

My travels to Utah this week were in no way like those of John Wesley Powell in 1869 on his 900-mile journey down the Green and Colorado Rivers. I hopped a 2-hour flight from Seattle to Salt Lake City, with dry bags packed full of UV-resistant, waterproof gear and all my tech necessities to document the journey and stay connected to the outside world. Powell, on the other hand, traveled by train, carried ammunition, and brought scientific equipment including sextants and chronometers in his wooden boats to chart the “Great Unknown,” including a harrowing final stretch through the then unexplored Grand Canyon. His journey provided the first scientific understanding of the topography and natural resource potential of the Colorado Basin, and helped fuel the growth and development of the western U.S. 

Powell immediately understood that the waters of the Green and Colorado Rivers were a valuable and limited natural resource, requiring thoughtful management to support western development. Today, we continue to grapple with the complexities of managing this limited resource utilized by over 40 million people across nine states and Mexico. The waters supply irrigation for agriculture, habitat for endangered species, and drinking water and hydroelectric power for downstream metropolitan areas. The USGS, the nation’s largest non-regulatory earth-science agency, monitors river flows and water quality across the nation, including in the Colorado Basin. Check out our current river conditions as we float down Desolation Canyon to Green River, Utah (

As a Water-Quality Hydrologist for the USGS, I’ll be part of a team measuring and recording the quality of the river water and sediment throughout our journey, to learn more about impacts from natural geology, a changing climate, and human influence. Human activities can change the timing and delivery of water, sediment, and contaminants in river systems. We’ll measure temperature, salinity, sediment, and microplastics. That last one - microplastics - was something Powell did not contend with. It is an emerging issue today - we are trying to understand occurrence of plastics (like fibers from clothing and pieces of degraded bottles) in the environment and impacts on biota, both from the plastic particles themselves and from the contaminants they may carry. The data we collect on this journey will provide new information about the quality of the Green and Colorado Rivers, that may support understanding resource availability, changes in that availability and decision making and management. Powell wrote that one purpose of his trip was “to add a mite to the great sum of human knowledge.” He added much more than a mite, and the learning continues today.