Upper Klamath Lake, Freshwater lake in Klamath County, Oregon.

Upper Klamath Lake is a shallow freshwater lake east of the Cascade Range in south-central Oregon, about 25 miles long and 8 miles wide, extending northwest from Klamath Falls at an average elevation of 4,140 feet. It is the largest body of fresh water by surface area in Oregon and the largest remnant of the ancient pluvial Lake Modoc. Its depth fluctuates between 8 and 50 feet due to water-supply regulation, and a short channel links it north to the smaller Agency Lake.

European fur traders from the Hudson's Bay Company reached the lake in 1826 and initially gave it a different name. This early exploration marked the start of outside contact with the water.

The Klamath name for the lake is ?ews, simply meaning 'lake'. The Klamath people lived around the lake and the Williamson, Sprague and Wood rivers, while the Modoc inhabited lands to the south. After the 1873 Modoc War, the Modoc were relocated to a reservation on the lake's north side.

The lake has several boat launch points that appeal to anglers looking to fish for trout. Check which access points are available and plan your visit based on seasonal conditions before you go.

The water serves as a vital stopover for millions of migrating birds traveling between continents each year. Visitors can observe hundreds of bird species here, including white pelicans that seek refuge on the lake.