

The following can be found at their site.
http://www.nps.gov/pais/planyourvisit/things2know.htm" onclick="window.open(this.href);return false;
Firearms
Loaded firearms are strictly prohibited. A Concealed Handgun License issued under the authority of the State of Texas, or another state, is not valid at the National Seashore.
Unloaded weapons may be possessed only when such weapons are rendered temporarily inoperable, or are packed, cased or stored in a manner that will prevent their ready use.

Someone please correct me if they are exempt from the new law.