REMOVE

1. trees
2. soil
3. rock
4. hills
5. roads
6. barriers

WHAT

1. banks (landforms) (1)
2. black-and-white film (1)
3. close-up views (1)
4. construction equipment (1)
5. construction sites (1)
6. cranes (equipment) (1)
7. exterior views (1)
8. Grand Coulee Dam (dam) (1)
9. machinery (1)
10. mountains (1)
11. rubbish (1)
12. scaffolds (1)
13. sky (1)
14. towers (single built work … (1)
15. utility poles (1)
16. Visual Works (hierarchy n … (1)

WHERE

1. Grand Coulee, Washington (1)

WHO

1. Clyfford Still; Still, Cl … (1)
2. Still, Clyfford (1)

WHEN

1. 1936 (1)
2. 1937 (1)
3. ca. 1936 - 1937 (1)