Back in time along the Big Wood

By Kurt Fesenmyer

 

Place an old photograph of a landscape next to one taken in recent times and you’re bound to see some change.  Depending on the landscape and how long it’s been since the original photo was taken, those changes might be minor – a few dead trees or a slight shift in a river’s course.  But changes that may be subtle over a few years can be pronounced when viewed over decades or centuries.  Scientists are increasingly turning to paired photos to convey major changes to our natural landscape, from changes in forest densities to shrinking of glaciers to changes in land use, because it really is true – a picture is worth a thousand words. 

 

Trout Unlimited, Wood River Land Trust, Bureau of Land Management, U. S. Forest Service and other partners recently commissioned a comprehensive assessment of the Big Wood River in Idaho to identify opportunities to improve the river’s health and address concerns related to changes to the fishery, lower flows, habitat loss, and increasing water temperatures. The report (available here) links much of the change in the health of the river to changes in the pattern of human land use along the river. As development in the basin has moved closer to the river, manipulations to the channel such as bank stabilization and alterations of the natural function of the river such as the removal of large downed trees followed so that the Big Wood has lost much of its ability to access its historical floodplain. That floodplain habitat serves a key role in storing sediment, reducing flood severity, a providing high quality fish habitat. The assessment outlines several restoration opportunities for improving the ecological and fisheries values of the river given the changes that have occurred.   

 

As TU and its partners gathered data for the assessment, Wood River Land Trust shared a set of aerial photos of the Big Wood from 1943.  TU’s science team created an interactive map viewer that allows you to take a tour of the basin and explore those changes to the landscape over the last 70 years that the assessment describes.  Click on the image below to explore the photos. You’ll see that the once broad cottonwood gallery forest that spanned the floodplain has been encroached by development, changing much of the river that Hemingway fished. You’ll also see portions of the basin that still retain much of the same character they had when recreational anglers were drawn to the landscape in the early 20th century.