Came in from the south gate 5 years ago. At the time we had a 39' fiver and a dually pickup. Stayed at the west gate - Grizzly RV park and left through the East. Intersecting the park everywhere except the north. I had no problems. It gets steep cliffs at the east.
Plan to go back in a year or two. Will have no issues taking our 42' MH through any of the park entrances. If these kind of things scare you - I'm not sure about coming up to the west gate, from the west. But it looks like there would be a lot of mountian driving that way too.