There are two entrances to Henry Cowell. The n. Big trees lot has 3 day use spots for large RVs. Access via hwy 9. Tge are also a few commercial RV parks further south on hwy 9 if looking for extended stay. The 2nd entrance is on Graham hill road, campground w a few RV spots. Make reservations.
I would call and ask...i remember camp grounds but not something as large as a 31 foot trailer
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