Christie’s announced Thursday that it will stage a single-owner sale of works owned by billionaire Bill Koch over two sessions on January 20 and January 21.

The “Visions of the West” sale will feature dozerns of works owned by Koch, with a heavy emphasis on American artists who depicted the American West and the frontier. Frederic Remington, Charles Marion Russell, and Albert Bierstadt are among the artists whose works are to be sold from the collection.

Koch, 85, is the lesser known of the four Koch brothers, with his siblings Charles and David—Bill’s twin brother—better known as some of the biggest donors to conservative causes over the last several decades. Bill had falling out in the 1980s with those brothers over the family business Koch Industries, and spent time working in an energy development company in Florida.

Bill also is an avid art collector, a passion that will be on full display at Christie’s. The sale there will include 16 sculptures by Remington, his painting Coming to the Call (estimated $6 million–$8 million), Russell’s work The Sun Worshippers ($4 million–$6 million), as well plenty of landscapes of the American West.