REMOVE

1. Geology
2. Gulf of Mexico
3. 1972

WHAT

1. Atlas Map (2)
2. World Atlas (2)

WHERE

1. Missouri (2)
2. United States (2)
3. Iowa (1)
4. Saint Louis (Mo.) (1)

WHO

1. Gamble, W.H. (2)
2. Mitchell, Samuel Augustus … (2)
3. S.A. Mitchell Jr. (2)
4. U.S.C.S. Dept. (2)
5. Williams, W. (2)

WHEN

1. 1868 (2)