I'm no expert, but have a daughter and family who moved to the Pullman/Moscow area 18 months ago, and I've visited twice -- this summer and last. Not sure where in the area you'll be, but a couple suggestions would be: try high ground a time or two; Steptoe Butte and Moscow Mountain are good starting points. Palouse Falls is interesting and surprising. It faces west, so afternoon light can be harsh, but I got a few decent shots with the sun overhead, nonetheless. Early evening, with building thunderstorm clouds in the east could be terrific. Dusk light can really "paint" the hills, especially if you arrive before harvest is totally complete. (not sure when in the summer the wheat is all finished) Those cloud formations tend to build during the day and can be really dramatic. There are dozens of side roads to try -- they make it easier to pull over at a moment's notice without getting run over by traffic; grab a local map of whatever area you're in. Check the weather forcasts and try for dawn or dusk on the sunniest days -- and that far north, those are really early and really late! And lastly, find the website of Alison Meyer and check out her work; there will be some specific places mentioned, but mostly it will give you some ideas and plenty of inspiration. Have fun!!
--Ron