REMOVE

1. telephone poles
2. figures (representations)
3. oil paint (paint)
4. hills

WHAT

1. Grand Coulee Dam (dam) (1)
2. Visual works (hierarchy n … (1)
3. boats (1)
4. construction equipment (1)
5. construction sites (1)

More 

WHERE

1. Nespelem, Washington (1)

WHO

1. Still, Clyfford (1)

WHEN

1. 1936 (1)
2. Regionalist (American Sce … (1)