The AQUATOX model (Release 3.2, https://www.epa.gov/hydrowq/aquatox) was parameterized and applied to The Loch in Loch Vale watershed in Colorado. The data were provided by the USGS supported Loch Vale Watershed Long-term Ecological Research and Monitoring program. This dataset is associated with the following publication: Clough, J., B. Rashleigh, R. Parmar, K. Wolfe, C. Knightes, and D. Smith. Modeling water quality in a subalpine lake. ECOLOGICAL MODELLING. Elsevier Science BV, Amsterdam, NETHERLANDS, 507: 111172, (2025).