Do your Expedia or Kayak search. Most of the reasonable places that are close are full. We got rooms at the casino in Black Hawk one mile away. The hill climb website has a list of motels. http://hotrodhillclimb.com/attend/
I think the best bet is to get a room in Golden or west Denver. From there it's only about 30 minutes drive to Central City. Denver rates will be better 'cuz they don't know about any "special event" going on.
@goatboy search hotrod hill climb and tons and tons of threads should pop up Here is @travisfromkansas coverage of last years event. 8 pages worth! http://www.royboyproductions.com/2016/09/17/2016-hot-rod-hill-climb-part-1-brought-speedway-motors/ Official web page http://hotrodhillclimb.com/ @7&7 probably because he wants somewhere to sleep. But I guess if he posted hoping to find someone with a shitty attitude you've got that base covered. He should be all sorted now.