Is early check in possible?

Yes, as long as the site is empty.

Yes if theres no one in your site from the night before

4 sure

Yes! There are 1st come/1st serve self registration sites. You'll know the site is empty if there is not a tag on the site # . So when you self register, grab the little ticket envelope 1st. Pick your site. Fill out the stub that you need to keep clipped at the site #. Then seal your check or cash in the envelope part and drop it in the secured drop tube! You're good to go!