Figure 6: Comparison of Uinta Mountain lake nitrate sample isotopic compositions from five national parks in the US Cordillera.
From: Agriculture causes nitrate fertilization of remote alpine lakes
(a) δ18O- versus δ15N-NO3− and (b) NO3− concentration versus δ15N-NO3−. The ellipses, which outline the 50% confidence level of each location (grey outline for Rocky Mountain sites, red for Uinta Mountains), are used to visualize each group of lakes and the overlap among the sites. Yellowstone National Park is represented by a single measurement. Data for sites other than the Uinta Mountains are from Nanus et al30.
