There is a length requirement to get in the park its on the website
At the General Sherman Parking lot, there is a special lot. There are numerous signs stating that large vehicles are not allowed. You should check their website and map as some of the roads don't support or allow them if I am remembering correctly.
Like Harry said, there is at the General Sherman lot, not much anywhere else that I noticed. I did see smaller RVs driving around though.
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