By default, Colorado has been doing this type of thing for quite some time. No real advertising/marketing, the MTBers just show up and decide to practice first, then race. Some have even sold their DH and DS rigs and got into the sport full time because i”t’s so much cheaper and so much more down to earth.” Not my words, but the words of a converted MTBer. I’d have to agree with him, though.
The MTB scene was great for indoors racing, when the DH and DS seasons are done. Scary part is when the roadies think it’s a good idea to get on a BMX bike. Entertaining for almost everyone but the medics. All that speed and no coordination makes a 17 Novice moto look like an Elite Class Main.