It is possible to start your own race sanctioning body. Write a business plan. Get a lawyer who handles corporations and set it up as a business (pick a type of incorporation that limits your own personal liability).
Then hire some officials, and the group of you write down what the racing and technical rules will be. (Big Bill France got this started by getting a bunch of people drunk first...)
Run those rules past racing insurance companies, and massage the rules until you can get affordable underwriting.
Then find suitable venues for your races. I notice you implied that you want to use government owned land - better get permission (in writing) first or they will shut you down permanently in a heartbeat. Same thing with privately owned land (unless you own it yourself). If you will create race courses out of random trails you'll probably find that the local government and your insurer will require you to make a lot of changes to those trails before they allow you to hold races. You'll also want to build ways to control track entrance and egress, ticketing, seating, concessions, rest rooms, lighting, and a public address system... and hire people to help you operate the races and care for the track between races and don't forget medical crews too... good thing you've got lots of money and political pull.
Then promote the heck out of your planned races. Don't forget to market it to both potential fans and racers. BTW, merely using free social media probably won't cut it.
You may have to start by holding free or cheap practice sessions. Expect push-back from potential racers who don't like something about your rules, but don't just give in to them (protect your business model). You might have to prove you can pay promised purses by putting money into escrow.
Make sure you promote and pay off every race on your promised schedule. Hope that the weather cooperates. Missed races or payouts under new sanctions can be death.
Lots of luck! Let us know your progress.
