Donaca Lake is a 3-acre (12,000 m2), 41-foot (12 m) deep lake in Linn County, Oregon, United States. It lies at an elevation of 2,700 feet (820 m). The lake can be accessed via two different trails, one from the south and one from the north. The lake is located within an old growth forest in the Middle Santiam Wilderness near Sweet Home. Donaca Lake provides habitat for a unique strain of cutthroat trout and affords excellent fishing for lively 8-to-12-inch (20 to 30 cm) specimens. Though not required by law, catch and release methods are encouraged to protect this fishery.