Ruth Lake sits approximately 30 km northeast of 100 Mile House in British Columbia's Cariboo region, within the traditional territory of the Secwepemc First Nation. The lake rests at 863 m elevation, covers 2. 84 km², and reaches a maximum depth of 20.

7 m, with an irregular shoreline fed by several unnamed inlet streams. Ruth Lake Park is a recreational day-use area popular with local residents for swimming and fishing.

A grassy area overlooks a small beach, while the remainder of the park is undeveloped forest. The lake supports rainbow trout, kokanee, burbot, and several other native species, making it a draw for anglers.

A valid British Columbia fishing licence is required. There are no lifeguards, no roped swimming area, and no formal swimmer facilities on site.