Question: What Montana river was a dam built on under the Columbia River Treaty?

Libby Dam is a dam on the Kootenai River in the U.S. state of Montana. <SEP>  Four dams were constructed under this treaty: three in British Columbia, Canada (Duncan Dam, Mica Dam, Keenleyside Dam) and one in Montana in the United States (Libby Dam). The Columbia River Treaty is a 1964 agreement between Canada and the United States on the development and operation of dams in the upper Columbia River basin for power and flood control benefits in both countries.  The treaty provided for the sharing with Canada of one-half of the downstream U.S. power and flood benefits, and allows the operation of Treaty storage for other benefits.  The long-term impacts of the treaty have been mixed: while the dams have provided enormous economic benefits to British Columbia and the U.S. Pacific Northwest through hydroelectric generation and flood control, there are longstanding concerns regarding social and economic impacts to the local communities, and the environmental effects associated with the construction and operation of large dams. <SEP> The Pend Oreille River is a tributary of the Columbia River, approximately 130 mi long, in northern Idaho and northeastern Washington in the United States, as well as southeastern British Columbia in Canada.  In its passage through British Columbia its name is spelled Pend-d'Oreille River.  It drains a scenic area of the Rocky Mountains along the U.S.-Canada border on the east side of the Columbia.  The river is sometimes defined as the lower part of the Clark Fork, which rises in western Montana.  The river drains an area of 66800 km2 , mostly through the Clark Fork and its tributaries in western Montana and including a portion of the Flathead River in southeastern British Columbia.  The full drainage basin of the river and its tributaries accounts for 43% of the entire Columbia River Basin above the confluence with the Columbia.  The total area of the Pend Oreille basin is just under 10% of the entire 258000 mi2 Columbia Basin.  Box Canyon Dam is currently underway on a multi million dollar project for a fish ladder. <SEP> Mica Dam, a hydroelectric dam spanning the Columbia River 135 kilometres north of Revelstoke, British Columbia, Canada, was built as one of three Canadian projects under the terms of the 1964 Columbia River Treaty and is operated by BC Hydro.  Completed in 1973 under the terms of the treaty, the Mica powerhouse had an original generating capacity of 1,805 megawatts (MW).  Mica Dam, named after the nearby settlement of Mica Creek and its associated stream, in turn named after the abundance of mica minerals in the area, is one of the largest earthfill dams in the world.  The reservoir for the dam is Kinbasket Lake, which was created when the dam was built.  Water from the dam flows south directly into Revelstoke Lake, the reservoir for the Revelstoke Dam.  Mica Dam is the tallest dam in Canada and second tallest in North America after the Chicoasén Dam in Mexico and it is the farthest upstream dam on the Columbia River.  The dam's underground powerhouse was the second largest in the world at the time of its construction, and was the first 500 kV installation of sulphur hexafluoride (SF) insulated switchgear in the world.