REMOVE

1. sky
2. barriers
3. machinery
4. trees
5. fences
6. atmospheric perspective
7. rock

WHAT

1. Visual Works (hierarchy n … (1)
2. black-and-white film (1)
3. churches (buildings) (1)
4. clouds (1)

More 

WHERE

1. New Windsor, Maryland (1)

WHO

1. Campbell, Sandra L. Still (1)
2. Sandra L. Still Campbell; … (1)

WHEN

1. 1966 (1)
2. after 1966 (1)