ARRL is a membership service organization that has over 600,000 members in the United States, its territories and possessions. Also of interest is The ARRL Letter which is published on a weekly basis.
ARES--Consists of licensed amateurs who have voluntarily registered their qualifications and equipment for communications in the public service when disaster strikes.
RACES--Is a radio communication service of volunteer licensed amateurs officially enrolled in the local civil-preparedness agency having jurisdiction.
Las Vegas--Regional Skywarn Consists of licensed and non licensed weather spotters that report local weather conditions to NOAA for the prediction of weather related warnings.