REMOVE

1. rivers
2. sky
3. silver gelatin
4. scaffolds

WHAT

1. Visual Works (hierarchy n … (1)
2. banks (landforms) (1)
3. bridges (built works) (1)
4. buildings (structures) (1)
5. cityscapes (representatio … (1)

More 

WHERE

1. Spokane, Washington (1)

WHO

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

WHEN

1. 1920 (1)
2. 1930 (1)
3. circa 1925 (1)