The Mountain States Conference, also known as the Skyline Conference, was a college athletic conference based in the Western United States. The league was established in 1938 when the seven charter members (see below) pulled out of the Rocky Mountain Athletic Conference.
From 1938 to 1946, the conference was popularly known as the Big Seven. After Colorado left in 1947 to join the Big Six Conference (later the Big Eight Conference) the MSC became popularly known as the Skyline Conference or Skyline Six while the Big Six took over the Big Seven name. It became known as the Skyline Eight after New Mexico and Montana joined in 1951.
The conference dissolved in early 1962 after four of its members (BYU, Utah, New Mexico, and Wyoming) departed to form the Western Athletic Conference in July. Montana operated as an independent for one football season in 1962, until the formation of the Big Sky Conference in 1963. Colorado State became independent until it joined the WAC in 1968. Utah State operated as an independent for fifteen seasons, until it joined the PCAA in 1977.
BYU: from 1938-1962, now independent in football and in the West Coast Conference in all other sports
Colorado: left in 1948 to join the Big Seven Conference (whose members all moved to the Big 12 Conference in 1996); now in the Pacific-12 Conference
Colorado State: now in the Mountain West Conference
Denver: dropped football in 1961 and now competes in the Sun Belt Conference for most sports, including men's and women's basketball; announced move to Western Athletic Conference effective July 1, 2012
Utah: moved to the Mountain West Conference; now in the Pacific-12 Conference
Utah State: now in the Western Athletic Conference
Wyoming: now in the Mountain West Conference