A mile east of Denver International Airport, surrounded by undeveloped agricultural land, a haphazard-looking loop is carved into the ground. It hints at the site’s proposed future: a members-only racetrack that would be available solely to those able to pay tens or hundreds of thousands of dollars. “This isn’t a typical racetrack that people may imagine,” Adams County spokeswoman Nikki Kimbleton said in an email to BusinessDen.