1960 Census records list Montana's population as 674,767

1961 Air Force begins construction of Montana ICBM silos (Chapter 20)

1962 Cuban Missile Crisis (Chapter 20)

1964 Congress passes the Wilderness Act (Chapter 21)

1964 U.S. Supreme Court rules on reapportionment (Chapter 21)

1965 Yellowtail Dam completed (Chapter 20)

1966 Large-scale strip mining begins at Colstrip (Chapter 21)

1968 Congress passes Indian Civil Rights Act (Chapter 22)