Logan River Watershed
The Logan River watershed is located in the heart of the Bear River range with headwaters near the Utah-Idaho border. The river flows southwest through Logan Canyon - a landscape dominated by formerly glaciated peaks, limestone cliffs, and the occasional sinkhole. The underlying bedrock has numerous caves that create natural springs that contribute to the river’s year-round discharge. Near the canyon’s mouth, the river is dammed in three locations (First, Second, and Third dams) for hydroelectric power generation. After exiting the mountains, the river flows west through Cache Valley and is impacted by a mixture of agricultural and urban environments. The Logan River converges with the Little Bear River in central Cache Valley before flowing north to the main stem of the Bear River and Cutler Reservoir.
The Logan GAMUT
Logan GAMUT (Gradients Along Mountain to Urban Transitions) consists of five climate stations and five aquatic monitoring stations. The highest elevation climate station is located within the T.W. Daniels Experimental Forest (TWDEF)
at an elevation of 8600ft. Two climate stations, paired with aquatic stations, are located in upper Logan Canyon near the Beaver Mountain ski area. The higher of these two paired sites is near the headwaters of the Logan River in Franklin Basin. The lower site is in the vicinity of Tony Grove Road. There are two climate stations and three aquatic stations located along the Logan River in Cache Valley. At the mouth of Logan Canyon on the USU campus, a climate station (main campus) and aquatic station (USU Waterlab) help to monitor how water resources change as the landscape transitions from a natural mountain environment to an urbanizing valley. Finally, lower elevation climate and aquatic stations near Mendon Road help quantify the impacts of mixed urban and agricultural surface types on the river hydrology and ecology. Up to date provisional data for all installed sites can be found at: http://data.iutahepscor.org/mdf/Data/Logan_River/.
Climate Station Installation
Climate station sensors are mounted to a 20ft tower embedded in concrete. Since many of the sites are located in backcountry settings, almost all the construction was done by hand.
The first step in raising the tower is to dig a hole. This is fairly easy in the fine river/lake sediments of Cache Valley, but is much more challenging when the subsurface consists of glacially deposited boulders as is the case at many mountain sites.
The concrete base is then mixed by hand in wheelbarrows. In some cases both dry concrete and water needed to be packed into the sites. At Knowlton Fork in Red Butte Creek, about 20 graduate student, undergraduates, and postdoctoral associates were recruited to do the heavy lifting.
Before the concrete is added to the hole, the tower is assembled, hoisted into place, and secured using guy lines.
Once the concrete has hardened, the sensors are attached to the tower at various levels on crossarms. An enclosure is attached to the base of the tower and securely houses the datalogger (station computer) and battery.
Finally, the sensors are connected to the datalogger. Typically, the sensors output a voltage. The datalogger measures the voltage and converts it to an environmental observation.