Blue River Reservoir, Reservoir in Lane County, Oregon, United States

Blue River Reservoir is a man-made lake in a forested valley in western Oregon, east of the small town of Blue River. It is held back by a dam and has two boat ramps and two campgrounds sitting along its shoreline.

Blue Lake Dam and Saddle Dam were built by the US Army Corps of Engineers in 1968, about 2 miles (3.2 km) from the mouth of the Blue River on the McKenzie River. They created the reservoir for flood control and irrigation. The impoundment of the Blue River formed a lake about 6 miles (10 km) long in the Willamette National Forest.

The reservoir is stocked with rainbow trout and holds native coastal cutthroat trout, so anglers fish it year-round; trout are the main catch, with hatcheries supplying part of the stock. The Forest Service runs Mona Campground on the north shore and Lookout Campground on the northeast side, and two boat launches serve motorized and non-motorized craft.

The reservoir is reached by turning off the main road east of the town of Blue River onto a forest road that leads to the water. There are no toilets or drinking water on site, so visitors should bring everything they need and watch out for submerged logs in shallow sections.

When the water level drops in autumn and winter, old tree stumps and remnants of the valley floor that normally sit under water become visible. This low-water period actually opens up quieter stretches of the reservoir to kayaks and rafts that cannot reach them when the lake is full.