This one doesn’t work for a TCMS. Check this out:
Campground Guidelines
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Fireworks and Firearms are prohibited on park property. Includes BB, Airsoft and pellet guns.
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http://www.jellystonetexas.com/Guidelines.aspx?Type=Campground
The place we stayed this year had the same rule. What they don’t want is for folks to go around shooting off fireworks or each other.