Emerald Lake is a lake located in the Trinity Alps Wilderness area, in Northern California. The lake sits in a granite bowl, approximately 5,500 ft (1,700 m) above sea level. It is dammed with a rock wall constructed many years ago when the area was used by miners. Visitors can still find old rusty pieces of their equipment around the lake, including giant gears, winches, and cables. Visitors can access the lake by hiking the , and the lake is downstream of Sapphire Lake.