2025-2026 Student Research Findings | Colorado Mesa University

Evaluation of Water Quality In James M. Robb State Park Lakes And Snook’s Bottom Lake

During the 2025 field season, a baseline water quality assessment was conducted on three lakes in Fruita, Colorado: Red Rock Lake, Bookcliff Lake, and Snook’s Bottom Lake. Red Rock Lake and Bookcliff Lake are located within James M. Robb Colorado River State Park, while Snook’s Bottom Lake is managed by the City of Fruita. These lakes have been used for recreation, fisheries, and irrigation. This project established baseline conditions that can be used for current management of the lakes and detecting future changes.

This project looked at the water quality of three lakes in Fruita, Colorado: Red Rock Lake, Bookcliff Lake, and Snook’s Bottom Lake. These lakes are near the Colorado River and are important for fishing, boating, wildlife, and irrigation. The water was tested from spring through fall to learn about temperature, oxygen levels, salt levels, and other basic water conditions. We found that Red Rock Lake had the most stable and healthy water overall for fish, boating, and irrigation. Bookcliff Lake had very high salt levels, which can make it hard for fish and plants to live there. Snook’s Bottom Lake got very warm in the summer and had low oxygen in deeper water making it hard for fish to live there. By studying these lakes, we now have a better idea of their current health. This information can help local managers protect the lakes and keep them safe for people, fish, and wildlife in the future.

Methodology

Sampling occurred weekly throughout the summer season. Four locations were sampled at each lake, including two deep open-water sites and two shoreline sites. Vertical water column profiles were measured at 0.5m intervals from the surface to the bottom. Field measurements included temperature, dissolved oxygen, pH, specific conductivity, total dissolved solids, salinity, oxidation-reduction potential, alkalinity, and hardness. The Colorado River and Red Rock Inlet were also measured to compare lake conditions with source waters. All three lakes showed seasonal thermal stratification. This restricted mixing led to oxygen depletion and anoxia in the deeper layers of the lake during the summer months. Reducing environments were observed in deeper waters, and high hydrogen sulfide concentrations were detected in Snook’s Bottom Lake, indicating prolonged anoxia.

Results

Red Rock Lake displayed the most stable and moderate water quality conditions, with low salinity, moderate conductivity, moderate dissolved solids, and seasonal but limited anoxia in the hypolimnion. These conditions were likely moderated by inflow from the Colorado River via Red Rock Inlet. Bookcliff Lake exhibited the highest salinity, conductivity, total dissolved solids, and hardness, along with persistent anoxia in the hypolimnion. These patterns are likely due to high evaporation rates and limited flushing. Snook’s Bottom Lake showed the strongest and most persistent thermal stratification, elevated summer temperatures, high pH, and prolonged hypolimnetic anoxia with detectable hydrogen sulfide at the bottom layer.

Conclusions

Overall, differences among the lakes were strongly influenced by water source, temperature, and location. Continued monitoring is recommended to track long-term changes in salinity, stratification, and dissolved oxygen to support management decisions involving recreation, angling opportunities, and irrigation.

Our 2025-2026 Researchers

Toby Baltus

Student Researcher

Eriek Hansen

Professor of Biology

Our Collaborators

For This Research Project

We want to thank our amazing colloborators: James M. Robb Colorado River State Park, Colorado Parks and Wildlife, River Watch of Colorado, and the City of Fruita.