Ril Lake is located in the Township of Lake of Bays, in the District of Muskoka, Ontario, Canada at 45.170969N, 78.998209W.
The perimeter of the lake is approximately 18.5 km with an average depth of 10 m. The lake is primarily spring fed and supplemented by creeks and seasonal run-off. Ril Lake is located in the Precambrian Shield area of northern Ontario, consisting of underlying granite bedrock overlayed with 1.5 to 6 m of soil, often with rocky granite outcroppings.
The north-eastern area of the lake is more developed with lots ranging from 15 to 30 m of waterfront and developed shoreline. The south-western area of the lake is less developed with lots ranging from 120 to 915 m. Ril Lake is designated as a "Category 2" lake by the Province of Ontario, reflecting its sensitivity to environmental damage and placing restrictions on future development.
Local forest is a mix of deciduous and conifer trees. Local wildlife includes; turtles, deer, moose, beaver, bear, fox, otter, racoon, turkey, and porcupine. A wide range of bird species are known to frequent the lake including; loon, heron, owls, ducks, raven, and woodpeckers. The fish population is made up of mostly small and large-mouth bass.