 Three states — Hawaii, Nevada, and Wyoming  — allow each county to establish its own regulations.For example, in Nevada, Clark County, where Las Vegas is located, allows residents to purchase and use only non-explosive and non-aerial consumer (safe and sane) fireworks during the 4th of July.Nye County allows persons 18 years of age or older to purchase and use safe and sane and all consumer fireworks on private property or at free designated launch pads.