If you are visiting in the Palouse region for a few days, a side trip to Palouse Falls State Park is a must. It is located about two hours from Pullman, Washington. It is best to shoot the falls at mid-day and through the afternoon. This is convenient in that you can shoot sunrise at a favorite location around Colfax in the morning and then head to the falls.
Palouse Falls plunges about 200 feet into a deep pool surrounded by rock. The whole area is actually a deep canyon and thus the necessity of shooting mid -day so the falls and canyon will be lighted as the sun is overhead. This is one of the more difficult falls to shoot and get a good image because the light is tricky and can be very harsh. In addition early in the season the water in the falls looks brown like chocolate milk from the dirt that is being released in the river upstream. Later in the season when the water is clear the falls diminishes in its volume. When the light is right you can see a rainbow in the mist. I have found the best time to photograph is late May and June.
There is also some wildlife in the area that includes marmots, deer and several species of birds. In addition images of the actual canyon itself are interesting and there are several trails in the area for hiking.
I would suggest eating before you go and bring plenty of water because there is very little in the way of civilization in this area. Hopefully, you will take the time for the trip as it can offer a very rewarding photographic experience.