Lake Keewahtin (formerly known as Sylvan or Halfbreed Lake) is a deep lake with excellent water quality. The lake does not drain (it's landlocked) and it has rich fen floating mats south of the lake that have been identified for preservation in past studies (CLFLWD, 2007). Lake Keewahtin is known for its excellent water quality.
The lake likely maintains its high quality through relatively low pollutant concentrations entering from its drainage area and a high rate of exchange with groundwater. A 2007 study found that panfish are abundant but top predators account for the majority of the biomass. The rough fish population was considered stable as carp were not collected in survey. The plant community was very diverse with curly-leaf pondweed present but not out competing native species. The overall management for the lake and watershed is focused on protection activities.