Several points here.  First check out mountaindirectory.com.  We have found this program to be very helpful in identifying potential problem areas.  It covers all sorts of info about % of grade and other concerns for RVs and trucks.  Second, there is a tunnel on the east side of the lake that has a height restriction.  We are 12'10" and chose to ignore our GPS warning to take the long way around the lake.  We made it thru the tunnel but had to drive down the middle and block both directions.  We made it but it was nerve racking.

Finally, there is a great municipal campground at the south end of the lake.  It is called "Campground by the Lake".  I'd suggest making reservation as early as possible.  We stayed there and found the sites to be big, full hook up and convenient to the entire area. The scenery around the lake is spectacular. Have a safe journey.