I remember as a child going camping with my folks and my dad would take our RV down the steepest grades and the most narrow roads. I remember looking out the window and not seeing the road but a sheer cliff 100 feet down. My dad was an excellent driver! How did he know how to navigate those roads so well?
Many people who go camping like to do so in the mountains, and Washington has many great mountain camping destinations. Driving a motorhome over steep hills, especially through a mountainous pass, can be stressful. You may find gas powered motorhomes are a little more difficult to control on a steep grade.