I don't recall the elevation near the gates. The campground is easy to miss because of the short downhill that precedes it and the desire to maximize one's momentum as the road curves right and climbs again.
Here is a google map. The starting point is the lot near the gate and the end point is the entrance to the campground. It is .3 mile.
http://maps.google.com/maps?saddr=CA...1,0&sz=19&z=19
zoom in and out to orient yourself as to where this is on Hwy. 39