White Bird Hill, just north of the town of White Bird is the steepest grade you will find on 95. As Texas Bubba said, it is between Riggins and Grangeville. There are pullouts and it is 2 lanes in each direction so people can pass you. Take it slow and steady and you will be fine. US 95 between New Meadows and Riggins usually during the summer has construction work taking place, this section is 2 lanes with passing lanes every once in a while, so you may have to wait for a pilot car. It usually doesn't take too long.