we have traveled that road twice. It's 4 lane, don't recall any major hills. We've been to Sam A Baker State Park twice and took that route both times in our 34' Class A with toad. PS.. Sam A Baker State Park is one of our favorites. The only negative is poor cell signal. You can use Google Maps to put in the route and select earth view and zoom in to see the road. You can almost read the license plates of the vehicles!
Lonny & Diane
2004 Country Coach Allure 33' "Big Blue"
Towing 2008 Chev Colorado 4x4
Semper Fi