We stayed at the Yosemite RV Resort in Coursegold. Book the VIP pull-through site for your "big rig". The rating is not that great, but it's fine as a base to see Yosemite. It's about an hour drive to the Valley floor.
The south entrance includes a picture stop with a view of all the highlights in the Park.
Side note, they included this view point in the Big, Big Trailer movie. The view hasn't changed in 60+years.
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