It’s cheaper to take a whole vehicle in than two individuals on foot for most parks, and even for the America the beautiful pass they only check the ID of the passholder. There’s pretty much no way they could enforce this so long as at least one person in the vehicle is a citizen or can pass as one.
How will they know if I’m a citizen? Do I need ID to visit the park?
It’s cheaper to take a whole vehicle in than two individuals on foot for most parks, and even for the America the beautiful pass they only check the ID of the passholder. There’s pretty much no way they could enforce this so long as at least one person in the vehicle is a citizen or can pass as one.