Ultra4 is a vehicle type, class, and series. Ultra4 Racing was born from the popularity of the annual Griffin King of the Hammers, considered to be the toughest one-day off-road race. The vehicles are unlimited four-wheel drive, capable of competing in multiple racing disciplines - extreme rock crawling, high-speed desert racing and short course. In five years, the sport has grown significantly from the inaugural King of the Hammers to an eight race national series including a regional east and west championship and a three-race pro series. Ultra4 Racing is managed by Hammerking Productions located in Lake Arrowhead, CA. To learn more, log on to www.ultra4racing.com.