Besides a thick haze of smoke, this image also captures a dramatic change in land cover in Washington state, changing from densely vegetated near the Pacific Coast to sparsely vegetated on the Columbia River Plateau near the Idaho border.Not much. (click for full-size)
Briefly, this crop extends from the eastern flank of the Washington Cascades on the west (left) edge to the Rocky Mountains of western Idaho on the east, and from northernmost Oregon to northern Washington, south and north respectively. The Snake River can be seen making an arc from the SE corner around the Wallowa Mountains to its confluence with the Columbia River in the southern middle of the image. Along the middle-western top edge, one can see the snake-shaped Lake Chelan, a glacially-carved and morain-dammed remnant of the ice ages.
Another ice age feature of particular interest is the scarring from the Missoula floods in the area north of the Snake and to the east of the Columbia Rivers. The darker channels are underlain by very raw, unweathered basalt; basically all soil was removed by the flood events. Lower ground near water sources can be irrigated, and lower elevations to the west have more rain and a longer growing season, allowing a variety of crops to be grown. Central Washington is known for its orchards (apples, pears, cherries, apricots, etc.). Farther to the east, the dissected, incised loess plains are very fertile, but are too dry for many crops. Wheat, however, grows quite well. Much of the wheat grown in this area is shipped via the Columbia River (or transported by rail to Portland, Or. and transferred to ships) and exported to Asian markets.
There's an awful lot to say about these sorts of images beyond "Oooo, Looky! Smoke!"