You don’t, and the trails I ride on allow them. In Boulder County, that’s not the case. I ride in other counties. But thanks for the lecture, dad.
Regardless, it makes zero logical sense to ban a 2 horsepower, silent, electric motor vehicle that is lighter and slower than a mountain bike, but allow mountain bikes. It’s hippie logic: horsepower produced by human legs augmented by fancy mechanical gears and chains is “natural” enough to allow, but if it’s powered by something else, ban it before the heathens desecrate the sacred space.
Thankfully, most of Colorado is people stoked about what they are doing, instead of pissed about what others are doing. You fall into the latter category. Boulder is your kind of place. Meanwhile, I’ll be somewhere else menacing the public safety with a 25 pound vehicle with a top speed of 18 mph.