Diamond Lake is a large natural lake located in southern Oregon, United States. It is situated at an elevation of about 5,200 feet (1,580 meters) above sea level in the southern part of the Cascade Range, within the boundaries of the Umpqua National Forest.
The lake was formed thousands of years ago by glaciers during the last Ice Age. It is around 3 miles (4.8 km) long and 1 mile (1.6 km) wide and has a maximum depth of 329 feet (100 meters), making it one of the deepest lakes in Oregon.
Diamond Lake is a popular recreation destination, especially for fishing, boating, and hiking. The lake is well known for its trout fishing, with both rainbow and brown trout present. The surrounding area also has a number of hiking trails, including the 3.3-mile (5.3 km) Mount Bailey Trail, which offers stunning views of the lake and surrounding mountains.
In the winter, the Diamond Lake Resort offers a range of winter sports activities, including skiing and snowboarding, snowshoeing, and snowmobiling. The resort is located on the northeast side of the lake and is accessible by Highway 138.