On top of the steep downgrade just north of Lewiston, you'll have a steep downgrade at Whitebird. From there you'll have some other downgrades between there and Weiser before taking I-84 East to Boise. Lewiston and Whitebird are the two steepest and longest. Go online - Youtube and you can search for both.
2011 Bighorn 3055RL, 2011 F350 DRW 6.7L 4x4 Diesel Lariat and Hensley TrailerSaver BD3, 1992 Jeep ZJ and 1978 Coleman Concord Pop-Up for remote camping
Dave & Renee plus (Champ, Molly, Paris, Missy, and Maggie in spirit), Mica, Mabel, and Melton