Builders FirstSource is the nation's largest building materials supplier. Our Kalispell MT Millwork proudly serves builders, contractors & remodelers in Kalispell and surrounding Montana-Wyoming Area with their building supply & construction needs. This facility offers the following building supplies & services: Doors & Millwork, Windows, Design Center & Showroom, Business Center, Pro Retail Store, Customer Pick Up | Will Call. Visit us today to discover why we are known as builders' first choice!