When you do the sort of “good enough” research I do for this site, it is hard to figure out exactly what they grow in Palouse. There is the Wikipedia answer, which mentions wheat and legumes, mostly lentils. But they seem to grow more just by looking at the colors, and when you try going beyond Wikipedia on Palouse, you mostly find the uninformed speculation of other photographers. I’ve heard and read that they grow canola (originally rapeseed), mustard, and any other variety of grains or grain-like plants. The bottom line is I don’t know what this is, but it’s pretty.