REMOVE

1. Photographs
2. Rivers.
3. National parks & reserves.
4. Library of Congress Prints a …

WHAT

1. National parks & reserves … (2)
2. Nitrate negatives (2)
3. negative (2)

WHO

1. Genthe, Arnold (2)
2. Library of Congress Print … (2)

WHEN

1. 1869-1942 (2)
2. 1903 (2)
3. 1906 (2)
4. between 1903 and 1906 (2)