If you enjoy steep hills, then try this one (map). I chickened out and turned around. It was almost a 45 degree slope at its steepest and covered in loose dirt with some small rocks (no bigger than baseball size). Too steep to even walk down. There's more traction a few feet off the road. I'm sure my car could handle the hill. And why not? It won't have a heart attack half way up.
The road is south of Barstow and easy to get to. Either take Camp Rock Road down to route 7525 then head south and turn east on 6640, or take Highway 247 (Barstow Road) to route 6640 and head east.